1 2 3 4 UNITED STATES DISTRICT COURT 5 NORTHERN DISTRICT OF CALIFORNIA 6 7 COLUMBIA INSURANCE CO., et al., Case No. 19-cv-04683-TSH

8 Plaintiffs,

ORDER GRANTING DEFENDANT’S

9 v. MOTION TO BIFURCATE

10 SIMPSON STRONG-TIE COMPANY Re: Dkt. No. 211

INC.,

11 Defendant. 12

13 14 I. INTRODUCTION 15 Plaintiffs Columbia Insurance Co. (“Columbia”) and MiTek Inc. (collectively “Plaintiffs”) 16 filed a complaint for patent infringement against Defendant Simpson Strong-Tie Company Inc. 17 (“Simpson”). ECF No. 61 (First Amended Complaint). Simpson filed a counterclaim for patent 18 invalidity against Plaintiffs. ECF No. 64. Pending before the Court is Simpson’s Motion To 19 Bifurcate, in which Simpson requests the Court separate the trial into two phases under Federal 20 Rule of Civil Procedure 42(b). ECF No. 211 (“Mot.”). For the reasons stated below, the Court 21 GRANTS the motion.1 22 II. BACKGROUND 23 The facts of this case are well known to the parties, and the Court has previously 24 summarized this case’s background in its order on the parties’ cross-motions for summary 25 judgment. ECF No. 200 at 2–8; see Columbia Ins. Co. v. Simpson Strong-Tie Co. Inc., No. 19-cv- 26 04683-TSH, 2025 WL 1999912 (N.D. Cal. July 17, 2025). The Court incorporates by reference 27 1 the factual background set forth therein. 2 Columbia, located in Nebraska, is the owner of U.S. Patent No. 10,316,510 (“the ’510 3 Patent”), entitled “Hanger for Fire Separation Wall,” which is the patent-in-suit. First Amended 4 Complaint (“FAC”) (ECF No. 61) ¶¶ 1, 7, 15. MiTek, located in Missouri, is the exclusive 5 licensee of the ’510 Patent. Id. ¶¶ 2, 16. MiTek manufactures and sells hangers used in building 6 construction and structures for connecting structural components to wall framing, such as trusses 7 and joists. Id. ¶ 17. Simpson is a California corporation that “has made, used, sold, or offered for 8 sale fire wall hangers that are adapted for connecting a trusses and joist to walls.” Id. ¶¶ 3, 25; 9 Simpson’s Answer to FAC ¶¶ 3, 25 (ECF No. 64). 10 Plaintiffs allege that Simpson’s products infringe Claim 40 of the ’510 Patent. FAC ¶¶ 54– 11 55. Simpson alleges that Claim 40 is invalid because it is anticipated by prior art, and it is obvious 12 over combinations of prior art. Simpson’s Cross-Motion for Summary Judgment on Invalidity at 13 9:28, 19:21–20:2 (ECF No. 142). 14 On October 28, 2024, Plaintiffs filed a motion for partial summary judgment, seeking 15 summary judgment on Simpson’s counterclaim that Claim 40 is invalid. ECF No. 86. In that 16 motion, Plaintiffs argued that under Post-Grant Review (“PGR”) Estoppel (35 U.S.C. § 325(e)(2)), 17 Simpson is estopped from asserting the Yamaguchi, Cullen, and Chapin references as prior art 18 against Claim 40 of the ’510 Patent. Id. at 1–2. Regarding PGR Estoppel, the parties engaged in 19 document productions and conducted discovery that included five expert reports and depositions 20 of six percipient and expert witnesses. Mot. at 3:5–12 (citing Declaration of Joseph V. Mauch ¶ 2 21 (ECF No. 211-1)). According to Simpson, the six witnesses relevant to PGR Estoppel are: 22 Eugene Lhymn, Drew Hirshfeld, Long Nguyen, Brian Hameder, Charlie Cypher and James 23 Martin. Id. at 3:12–20. Plaintiffs do not dispute that the PGR Estoppel issue involves these six 24 witnesses, but in their Opposition to Simpson’s Motion, Plaintiffs reference only Hirshfeld and 25 Lhymn. See Plaintiffs’ Opposition to Motion To Bifurcate (“Opp.”) at 9:16–21 (ECF No. 217). 26 The parties previously filed cross-Daubert motions to exclude various portions of these experts’ 27 testimonies. See ECF Nos. 84 (Plaintiffs’ Daubert Motion to Exclude Testimony of Hirshfeld, 1 Cypher, and Nguyen); 97-4 (Simpson’s Daubert Motion to Exclude Testimony of Lhymn).2 2 On May 30, 2025, the Court issued an order (1) concluding that Simpson is estopped from 3 asserting the Cullen reference in these proceedings; (2) granting Plaintiffs’ motion for partial 4 summary judgment as to the Cullen reference only; (3) denying Simpson’s Daubert motion; and 5 (4) granting in part and denying in part Plaintiffs’ Daubert motion. See ECF No. 151. On June 6 11, 2025, Simpson moved for clarification of the Court’s May 30, 2025, order. ECF No. 180. In 7 its order on Simpson’s motion for clarification, the Court stated:

8 Plaintiffs have correctly interpreted the Court’s order. The Court granted Plaintiffs’ motion as to the Cullen reference, meaning that 9 Simpson is estopped from asserting that reference. The Court denied Plaintiffs’ motion as to the Chapin and Yamaguchi references, finding 10 triable questions of fact concerning whether Simpson is estopped from asserting those references. Those triable questions of fact will 11 be resolved at trial. 12 ECF No. 190. A jury trial is scheduled for October 27, 2025. ECF No. 206. 13 In the parties’ most recent Joint Case Management Statement, Plaintiffs indicate that they 14 plan on asserting the defense of PGR Estoppel at trial. See ECF No. 201 at 9–10. Simpson filed 15 its instant Motion To Bifurcate on August 11, 2025. ECF No. 211 (“Mot.”). Simpson proposes 16 bifurcating the trial into two phases by

17 requesting the Court to conduct a bench trial on Plaintiffs’ equitable defense that Simpson is estopped from asserting certain prior art 18 references prior to any jury trial on the issues of whether Simpson infringes the asserted patent claim and whether the asserted patent 19 claim is invalid. 20 Mot. at 1:2–7. On August 18, 2025, Plaintiffs filed an Opposition. ECF No. 217 (“Opp.”). 21 Simpson elected not to file an optional Reply. See ECF No. 210 (Order on Expedited Briefing), at 22 2 (Simpson “agreed to forego a Reply Brief” unless “Plaintiffs found and rely on any case in 23 which PGR or IPR estoppel was decided by a jury, in a direct or advisory manner . . .”). 24 25 26

27 2 Simpson’s Daubert motion was filed under seal (ECF No. 97-4). The redacted version was filed 1 III. LEGAL STANDARD 2 A court may bifurcate a trial for “convenience, to avoid prejudice, or to expedite and 3 economize.” Fed. R. Civ. P. 42(b). Under Rule 42(b),

4 the court may order a separate trial of one or more separate issues, claims, crossclaims, counterclaims, or third-party claims. When 5 ordering a separate trial, the court must preserve any federal right to a jury trial. 6

7 Id. 8 A court has “broad discretion” in deciding whether to bifurcate. Zivkovic v. S. California 9 Edison Co., 302 F.3d 1080, 1088 (9th Cir. 2002) (citation omitted). “Bifurcation, however, is the 10 exception, not the norm as a single proceeding will generally be a more efficient and reasonable 11 means of resolving the action.” San Bernardino Cty. v. Ins. Co. of the State of Pa., No. CV-21- 12 1978-PSG(JEMx), 2023 WL 2629888, at *1 (C.D. Cal. Feb. 6, 2023) (cleaned up); accord GEM 13 Acquisitionco, LLC v. Sorenson Grp. Holdings, LLC, No. C-09-01484-SI, 2010 WL 1729400, at 14 *3 (N.D. Cal. Apr. 27, 2010). “Courts ‘consider several factors in determining whether 15 bifurcation is appropriate, including separability of the issues, simplification of discovery and 16 conservation of resources, and prejudice to the parties.’” Jones v. Nat’l R.R. Passenger Corp., No. 17 15-cv-02726-TSH, 2018 WL 6606247, at *4 (N.D. Cal. Dec. 17, 2018) (quoting McDermott v. 18 Potter, No. C-07–06300-SI, 2010 WL 956808, at *1 (N.D. Cal. Mar. 12, 2010)). “The party 19 seeking bifurcation bears the burden of showing that bifurcation is justified in the given 20 circumstances.” San Bernardino, 2023 WL 2629888, at *1 (citation omitted); accord GEM, 2010 21 WL 1729400, at *2. 22 IV. DISCUSSION 23 Simpson argues that “the Court should grant this Motion and order a separate bench trial of 24 Plaintiffs’ PGR Estoppel defense prior to the jury trial on infringement and invalidity.” Mot. at 25 2:17–18. Simpson asserts that “every factor that courts in this Circuit consider when deciding 26 whether to conduct separate trials of certain issues favors bifurcation here[.]” Id. at 1:13–15. 27 Plaintiffs contend PGR Estoppel “can and should be properly resolved in a single, unified trial 1 issues in patent cases.” Opp. at 3:1–3. Plaintiffs assert that Simpson’s Motion is “procedurally 2 improper and substantially unwarranted,” and “creates judicial inefficiencies for both the Court 3 and the parties, and greatly prejudices [Plaintiffs].” Id. at 1:3–20. 4 In sum, the Court finds that it is appropriate to exercise its discretion to conduct a bench 5 trial on PGR Estoppel prior to a jury trial on the remaining legal issues. Therefore, bifurcation of 6 the trial is warranted. 7 A. PGR Estoppel 8 The Court must decide whether it should order a separate bench trial on Plaintiffs’ PGR 9 Estoppel defense. As such, the Court first sets forth legal principles underlying PGR Estoppel. 10 Under the America Invents Act (AIA), the United States Patent and Trademark Office 11 (“USPTO”) may reconsider the validity of issued patents through post-grant review (PGR) 12 proceedings. Return Mail, Inc. v. United States Postal Serv., 587 U.S. 618, 622–24 (2019). The 13 PGR provision “permits ‘a person who is not the owner of a patent’ to petition for review and 14 cancellation of a patent on any ground of patentability.” Id. at 624 (quoting 35 U.S.C. § 321). 15 The PGR provision is interpreted in tandem with the inter-partes review (IPR) provision where the 16 two provisions contain identical language—thus, caselaw from the Court of Appeals for the 17 Federal Circuit regarding IPR applies equally to the PGR provision. Credit Acceptance Corp. v. 18 Westlake Servs., 859 F.3d 1044, 1053 (Fed. Cir. 2017). 19 Parallel proceedings occur when a patent is litigated both in district court and in USPTO 20 proceedings, such as through PGR. E.g., Apple Inc. v. Vidal, 63 F.4th 1, 8 (Fed. Cir. 2023). PGR 21 Estoppel applies in parallel proceedings that involve PGR proceedings at the Patent Trial and 22 Appeal Board (“PTAB”). See Credit, 859 F.3d at 1049 (“Once the Board issues a final written 23 decision, the estoppel statute applies.”). The PGR Estoppel provision states, in relevant part:

24 (2) Civil actions and other proceedings.--The petitioner in a post- grant review of a claim in a patent under this chapter that results in a 25 final written decision under section 328(a), or the real party in interest or privy of the petitioner, may not assert either in a civil action arising 26 in whole or in part under section 1338 of title 28 . . . that the claim is invalid on any ground that the petitioner raised or reasonably could 27 have raised during that post-grant review. 1 analyzing PGR Estoppel. See GREE, Inc. v. Supercell Oy, No. 19-cv-00071-JRG-RSP, 2019 WL 2 5677511, at *2 (E.D. Tex. Oct. 30, 2019) (observing “the PGR and IPR estoppel provisions are 3 substantively identical”). Because PGR Estoppel is a matter unique to patent law, Federal Circuit 4 law governs its scope and application. See Medline Indus., Inc. v. C.R. Bard, Inc., No. 17-c-7216, 5 2020 WL 5512132, at *2 (N.D. Ill. Sept. 14, 2020) (citing In re Cray Inc., 871 F.3d 1355, 1360 6 (Fed. Cir. 2017)) (in the context of IPR Estoppel). 7 PGR Estoppel is a statutory estoppel provision. See SynQor, Inc v. Vicor Corp., 988 F.3d 8 1341, 1347–48 (Fed. Cir. 2021) (discussing IPR Estoppel). As a form of estoppel, a defense 9 premised on PGR Estoppel is equitable in nature. See Robert Bosch, LLC v. Pylon Mfg. Corp., 10 719 F.3d 1305, 1309 (Fed. Cir. 2013) (“Where words are employed in a statute which had at the 11 time a well-known meaning at common law or in the law of this country, they are presumed to 12 have been used in that sense.”) (cleaned up); Heckler v. Cmty. Health Servs. of Crawford Cnty., 13 Inc., 467 U.S. 51, 59 (1984) (“Estoppel is an equitable doctrine invoked to avoid injustice in 14 particular cases.”). The purpose of the PGR Estoppel statute is indeed grounded in equity— “to 15 prevent parties from pursuing two rounds of invalidity arguments before the PTAB and the district 16 court.” GREE, 2019 WL 5677511, at *4. 17 PGR Estoppel “estops a petitioner as to invalidity grounds a skilled searcher conducting a 18 diligent search reasonably could have been expected to discover, as these are grounds that the 19 petitioner ‘reasonably could have raised’ in its petition.” Ironburg Inventions Ltd. v. Valve Corp., 20 64 F.4th 1274, 1298 (Fed. Cir. 2023) (in the context of IPR Estoppel). “The inquiry into what a 21 skilled and diligent searcher would reasonably have discovered is ultimately concerned with what 22 the searcher of ordinary skill would find through reasonable diligence and not what an actual 23 researcher in fact did find through whatever level of diligence she exercised.” Id. at 1299 24 (emphasis in original). “[T]he burden of proving, by a preponderance of the evidence, that a 25 skilled searcher exercising reasonable diligence would have identified an invalidity ground rests 26 on the patent holder, as the party asserting and seeking to benefit from the affirmative defense of 27 [PGR] estoppel.” Id. 1 e.g., GeigTech E. Bay LLC v. Lutron Elecs. Co., No. 18-civ-05290 (CM), 2023 WL 8827572, at 2 *1 (S.D.N.Y. Dec. 21, 2023) (holding “judges, not juries, decide what issues parties are or are not 3 legally barred from raising”); accord Innovative Memory Sys., Inc. v. Micron Tech., Inc., No. CV- 4 14-1480-RGA, 2022 WL 4548644, at *5 (D. Del. Sept. 29, 2022) (in the context of IPR Estoppel). 5 As with other patent issues, the ultimate determination on PGR Estoppel encompasses underlying 6 questions of fact. See Intex Recreation Corp. v. Bestway USA Inc., No. LA-cv-163300-JAK(Ex), 7 2023 WL 9687197, at *18 (C.D. Cal. Nov. 27, 2023) (noting the presence of “factual disputes 8 concerning whether a reasonably diligent searcher would have read, and interpreted, and 9 understood the references in the context of the patent as a matter of law”) (cleaned up); Pavo Sols. 10 LLC v. Kingston Tech. Co., Inc., No. 14-cv-01352-JLS-KES, 2020 WL 1049911, at *4 (C.D. Cal. 11 Feb. 18, 2020) (noting “the question of whether a skilled searcher, conducting a diligent search, 12 reasonably could have been expected to discover these prior art references, is a question of fact”). 13 But where there exists a genuine issue of fact regarding the application of PGR Estoppel, it is 14 appropriate for a court to resolve the factual dispute at a bench trial. GeigTech, 2023 WL 15 8827572, at *1. 16 Here, Plaintiffs plan on asserting the defense of PGR Estoppel at the parties’ upcoming 17 trial. See ECF No. 201 at 9–10. The Court previously found that issues of fact precluded 18 summary judgment on Plaintiffs’ PGR Estoppel defense regarding the Chapin and Yamaguchi 19 references. ECF No. 151. The parties disagree on whether those factual disputes should be 20 resolved by the Court in a bench trial or by a jury. Simpson argues that any remaining “questions 21 of fact” regarding PGR Estoppel should be resolved “in a bench trial prior to the jury trial.” Mot. 22 at 2:12–16. Plaintiffs have employed a shifting sands approach to whether the Court is the proper 23 factfinder for factual issues underpinning the application of PGR Estoppel. See id. at 3:21–4:20; 24 compare ECF No. 120 (Plaintiffs’ Reply in Support of Partial Summary Judgment) at 2 (“PGR 25 estoppel is an equitable defense that must be decided by the Court irrespective of any likely factual 26 dispute[.]”) with Opp. at 3:6–8 (“PGR estoppel, like other equitable claims and defenses, involves 27 threshold factual determinations that should be made by a jury when disputed.”). The Court 1 1:21–22. As such, the Court agrees with other district courts that have addressed this issue that it 2 is appropriate for the Court to resolve the factual disputes regarding PGR Estoppel in a bench trial 3 prior to a jury trial on the legal issues. E.g., GeigTech, 2023 WL 8827572, at *1; see Illinois Tool 4 Works, Inc. v. MOC Prods. Co., 946 F. Supp. 2d 1042, 1044 (S.D. Cal. 2012) (explaining in a 5 patent case that “[e]quitable defenses . . . are ultimately to be decided by the Court, not the jury”); 6 see also Mot. at 7:1–17 (collecting cases). 7 Plaintiffs’ assertion that “[t]he Federal Circuit has consistently recognized that juries must 8 resolve disputed facts even in the context of equitable defenses” is not supported by Federal 9 Circuit caselaw. Opp. at 3:8–9 (emphasis added). Plaintiffs go on to cite a panoply of cases that 10 hold a trial court has discretion in choosing how to resolve an equitable defense’s underlying 11 factual disputes. Id. at 3:11–23, 4:16–5:6; see, e.g., Hebert v. Lisle Corp., 99 F.3d 1109, 1114 12 (Fed. Cir. 1996) (“Some courts have reserved the entire issue of inequitable conduct unto 13 themselves; some have submitted special interrogatories to the jury on the facts of materiality and 14 intent; and some have instructed the jury to find and weigh the facts of materiality and intent and 15 decide the ultimate question of inequitable conduct, as in the case at bar. . . . [a]bsent a clear 16 showing of prejudice, or failure to achieve a fair trial, the district court's choice of procedure will 17 not be disturbed.”). Similarly, Plaintiffs’ pronouncement that “[t]he proper procedure” for 18 handling the PGR Estoppel issue is “the jury determines the underlying facts through special 19 interrogatories, and then the court applies the law to those facts,” finds no support in the relevant 20 caselaw. Opp. at 5:7–6:3 (emphasis added). Plaintiffs again cite to cases holding that a district 21 court may permit “juries to return advisory verdicts on equitable claims[.]” Id. (citing e.g., Am. 22 Calcar, Inc. v. Am. Honda Motor Co., 651 F.3d 1318, 1333–34 (Fed. Cir. 2011)). Notably, not 23 only is the choice to employ an advisory jury verdict within the province of the trial court, but 24 such a verdict is not binding on the court. Am. Calcar, 651 F.3d at 1333. 25 Overall, the parties have not identified—and the Court is not aware of any—cases where 26 PGR Estoppel, or IPR Estoppel, was tried by a jury, advisory or otherwise. See Mot. at 13:6–16. 27 Therefore, nothing in the background principles or caselaw associated with PGR Estoppel 1 addition to the caselaw specific to PGR Estoppel, the Court finds that the factors under Rule 42(b) 2 also favor bifurcating the PGR Estoppel issue. 3 Accordingly, the Court concludes that bifurcation is warranted. 4 B. Separability Of The Issues 5 Simpson argues that the issue of PGR Estoppel is separable from the issues of patent 6 infringement and patent invalidity because (1) Plaintiffs do not have the “right to a jury trial on 7 their equitable defense of PGR Estoppel”; and (2) the witnesses and the “body of law and facts 8 relating to PGR Estoppel [are] entirely different” from the jury issues of infringement and 9 invalidity. Mot. at 1:16–24. Plaintiffs contend that (1) a jury should resolve the factual disputes 10 regarding credibility; and (2) “the evidentiary presentations for both PGR estoppel and invalidity 11 could include substantial factual overlap.” Opp. at 6:4–20. 12 The Seventh Amendment to the United States Constitution preserves the right to a jury 13 trial for legal claims but not for equitable claims, such as a claim for injunctive relief. Danjaq 14 LLC v. Sony Corp., 263 F.3d 942, 962 (9th Cir. 2001); see U.S. Const. amend. VII (“In Suits at 15 common law, where the value in controversy shall exceed twenty dollars, the right of trial by jury 16 shall be preserved[.]”). Federal courts may separate legal and equitable claims “so long as the 17 legal and equitable issues are distinct.” Danjaq, 263 F.3d at 962. “When the legal and equitable 18 issues overlap and the evidence is intertwined,” however, “the district court must take care not to 19 impinge on the right to a jury.” Id. For that reason, in cases involving overlapping legal and 20 equitable claims, “the legal claims involved in the action must be determined prior to any final 21 court determination of the equitable claims.” Dairy Queen, Inc. v. Wood, 369 U.S. 469, 479 22 (1962). 23 In patent cases, a court my hold a bench trial on equitable defenses without violating the 24 Seventh Amendment when any factual disputes turn on different factual foundations from those in 25 the legal issues tried by a jury. See Agfa Corp. v. Creo Prods. Inc., 451 F.3d 1366, 1371–73 (Fed. 26 Cir. 2006) (affirming trial court’s decision to hold bench trial on inequitable conduct prior to jury 27 trial on patent validity because the two issues were not “common issues” that must be tried by a 1 bench trial. See Paragon Podiatry Lab'y, Inc. v. KLM Lab'ys, Inc., 984 F.2d 1182, 1190 (Fed. Cir. 2 1993) (“The defense of inequitable conduct in a patent suit, being entirely equitable in nature, is 3 not an issue for a jury to decide. . . . [t]hus, a disputed finding of intent to mislead or to deceive is 4 one for the judge to resolve, not the jury, albeit not on summary judgment if there is a genuine 5 dispute.”); see also Granite State Ins. Co. v. Smart Modular Techs., Inc., 76 F.3d 1023, 1027 (9th 6 Cir. 1996) (“A litigant is not entitled to have a jury resolve a disputed affirmative defense if the 7 defense is equitable in nature.”). 8 Here, the Court concludes that holding a bench trial on PGR Estoppel would not violate 9 the Seventh Amendment because—at least in this case—PGR Estoppel is not a common issue 10 with either infringement or invalidity. First, the Court’s resolution of factual disputes within PGR 11 Estoppel does not offend the Seventh Amendment. Plaintiffs do not argue that they have a 12 Constitutional right to a jury trial on their PGR Estoppel defense. Nor could they. Both Ninth 13 Circuit and Federal Circuit precedent squarely hold that no right to jury trial exists for equitable 14 defenses. See Agfa, 451 F.3d at 1371–73; Granite, 76 F.3d at 1027. Plaintiffs make a single 15 argument for why it is more appropriate for a jury to decide the factual issues than the Court: the 16 “key factual dispute centers on [Plaintiffs’] expert’s credibility,” and “[c]redibility determinations 17 are quintessentially within the province of the jury.” Opp. at 6:4–7. But this argument mimics 18 one rejected by the Federal Circuit. See Paragon, 984 F.2d at 1190 (rejecting argument that intent 19 element of inequitable conduct is an issue to be resolved by the jury and holding “[a] patentee has 20 no right to a jury trial respecting the factual element of culpable intent as part of the defense of 21 inequitable conduct”). 22 Second, Plaintiffs’ PGR Estoppel defense involves different witnesses, law, and facts from 23 the issues of infringement and invalidity. Regarding witnesses, Simpson argues that “[n]one of 24 the six witnesses who will testify in the requested bench trial regarding estoppel will have to 25 return to testify in the jury trial on infringement and invalidity.” Mot. at 9:8–10. Plaintiffs do not 26 respond directly to this argument but instead make the vague assertion that “the state of the art at 27 the relevant time period, which will be presented by both parties’ substantive experts, will 1 Plaintiffs do not indicate which witnesses will overlap in Simpson’s proposed bifurcated trial.3 2 And in fact, Plaintiffs did not rely on the witnesses that Simpson identified as pertinent to PGR 3 Estoppel in Plaintiffs’ briefing opposing Simpson’s motion for summary judgment on invalidity. 4 See generally ECF No. 157-2.4 Therefore, there is no indication that bifurcation will require 5 repetition of witnesses. 6 Regarding the legal and factual issues, Simpson argues that the issues “for the two trials 7 are entirely separate and distinct.” Mot. at 9:4–6. Plaintiffs contend that “[t]he scope and content 8 of the applicable prior art” and “the state of the art at the relevant time period” are “necessary for 9 the estoppel inquiry and Simpson’s obviousness challenge.” Opp. at 6:13–18. Tellingly, Plaintiffs 10 cite to no authority for this proposition. To be sure, Plaintiffs identify underlying factual inquiries 11 for obviousness. See Cont'l Can Co. USA v. Monsanto Co., 948 F.2d 1264, 1270 (Fed. Cir. 1991) 12 (citing Graham v. John Deere Co., 383 U.S. 1, 17 (1966)) (explaining that obviousness is a 13 question of law based on four factual inquiries, known as the Graham factors: “the scope and 14 content of the prior art, the differences between the prior art and the claimed invention, the level of 15 ordinary skill at the time the invention was made, and any objective considerations that may be 16 present”). However, the underlying factual inquiry for PGR Estoppel in this case is entirely 17 different—“whether a skilled searcher, conducting a diligent search, reasonably could have been 18 expected to discover these prior art references.” E.g., Pavo, 2020 WL 1049911, at *4. Elsewhere 19 in their brief, Plaintiffs unequivocally agree that this “is the factual question to be answered” 20 regarding PGR Estoppel. Opp. at 9:16–18. Thus, it is unclear why Plaintiffs posit that 21 obviousness and PGR Estoppel involve the same factual inquiries; the two issues clearly do not. 22 In sum, bifurcation would involve distinct legal and equitable issues. 23 Further, Plaintiffs’ reliance on the Court’s previous summary judgment order on PGR 24 3 In another section of their brief, Plaintiffs argue: “to the extent any substantive witness is 25 required to testify regarding the state of the art at the time of any search, or the scope and content of the prior art, the parties’ liability experts would be required to testify in two different 26 proceedings. This would lead [Plaintiffs] having to pay for certain witness expenses twice.” Opp. at 11:7–10. But again, Plaintiffs do not explain which witnesses would be repetitive. 27 1 Estoppel is misguided. Plaintiffs argue that the Court ruled “that there are questions of fact 2 remaining as to whether estoppel should be applied to the Yamaguchi and Chapin references” that 3 must be decided by a jury. Id. at 12:11–13:1. Not so. The Court explained—in its summary 4 judgment order on PGR Estoppel and again in its order on Simpson’s motion for clarification— 5 that factual disputes regarding PGR Estoppel existed. See ECF No. 151, at 26; ECF No. 190. 6 While the Court indicated that these factual disputes would be resolved at trial, the Court was not 7 asked to decide what type of trial would be most appropriate for these disputes. See ECF No. 190 8 (“Those triable questions of fact will be resolved at trial.”). 9 Accordingly, the Court finds that this factor weighs in favor of bifurcation. 10 C. Judicial Economy 11 Simpson argues bifurcation serves the interest of judicial economy because it reduces “the 12 length of jury trial by two or three days” and “potentially eliminat[es] the need for a jury trial 13 completely if Simpson is estopped from asserting all references.” Mot. at 1:25–27. Plaintiffs 14 contend that bifurcation would create “judicial inefficiencies for both the Court and the parties,” 15 and would require the parties “to expend resources on two trials, as opposed to one.” Opp. at 1:7– 16 8, 6:27–7:1. 17 “Bifurcation is often in the interest of efficiency and judicial economy when the resolution 18 of one claim may obviate the need to adjudicate one or more other claims.” Desmare v. New 19 Mexico, No. CIV-07–199-JB/RHS, 2007 WL 5231690, at *2 (D.N.M. Aug. 14, 2007) (citing 20 Mandeville v. Quinstar Corp., 109 F. App’x 191, 194 (10th Cir. 2004)); see also Amato v. City of 21 Saratoga Springs, N.Y., 170 F.3d 311, 316 (2d Cir. 1999) (explaining bifurcation appropriate 22 where “the litigation of the first issue might eliminate the need to litigate the second issue”). 23 Moreover, “[o]verlap in the evidence as between the two claims may militate in favor of one 24 slightly longer trial rather than two long trials.” Matsushita Elec. Indus. Co. v. CMC Magnetics 25 Corp., No. C-06-04538-WHA, 2007 WL 219779, at *2 (N.D. Cal. Jan. 29, 2007). 26 Here, the Court concludes that bifurcation would aid judicial economy. First, bifurcation 27 would promote efficiency because it is likely that a bench trial on PGR Estoppel will require fewer 1 promotes efficiency because “the Court is already well-versed in the facts, expert opinions, and 2 law that are at issue, based on the PGR Estoppel briefing.” Mot. at 10:10–13. Plaintiffs dismiss 3 this argument under the premise that if accepted, it “would mean that any case could meet the Rule 4 42(b) standard for bifurcation.” Opp. at 8:23–24. Plaintiffs contend that “in any trial,” the court is 5 well-versed in the legal and factual issues. Id. at 8:24–27. The Court disagrees. It is not in every 6 case that the court dives into extensive briefing and expert opinions prior to trial; however, this is 7 true for this case, where the Court previously ruled on a motion for partial summary judgment and 8 dueling Daubert motions regarding PGR Estoppel. See ECF No. 151. 9 Second, bifurcation promotes judicial economy because it is not likely to increase costs 10 and may result in less cost to the parties. There is no dispute that bifurcation would reduce the 11 number of days in the jury trial by at least the number of days required for PGR Estoppel. See 12 Mot. at 9:19–22; Opp. at 9:22–24. True, the number of days may not be reduced by more than this 13 amount, but it is salient that a determination on PGR Estoppel “may obviate the need to 14 adjudicate” one or more aspects of Simpson’s invalidity counterclaim. Cf. Desmare, 2007 WL 15 5231690, at *2, 9. Moreover, as discussed, there is no overlap in the evidence between PGR 16 Estoppel and infringement and invalidity that swings the judicial economy pendulum in Plaintiffs’ 17 favor. Thus, this case is unlike other cases where duplicative efforts in two trials led to increased 18 costs and decreased judicial efficiency. Contra Gravity Defyer Corp. v. Under Armour, Inc., No. 19 LA-cv-1301842-JAK(JCGx), 2013 WL 12138987, at *3 (C.D. Cal. July 23, 2013) (“Bifurcation 20 invites two rounds of discovery, with depositions of some the same persons taken more than once, 21 and additional potential for disputes.”). 22 Plaintiffs’ reliance on Jones v. National Railroad Passenger Corp. is misplaced. Opp. at 23 7:10–16 (citing 2018 WL 6606247, at *5). In Jones, the Court concluded that “bifurcation would 24 not aid judicial economy” where “bifurcation would require the Court to reopen discovery,” 25 thereby increasing the costs and duration of the litigation. Jones, 2018 WL 6606247, at *5–6. In 26 contrast, here, discovery for PGR Estoppel is closed, and the parties have already shepherded their 27 respective evidence in their briefs for summary judgment. Therefore, the concerns present in 1 Accordingly, the Court finds that this factor weighs in favor of bifurcation. 2 D. Prejudice 3 Simpson argues that “bifurcation results in no prejudice to Plaintiffs whereas failure to 4 conduct separate trials prejudices Simpson by forcing it to unnecessarily present its PGR Estoppel 5 case to the jury, which will significantly increase its costs and could cause juror confusion and 6 error regarding Simpson’s invalidity counterclaim.” Mot. at 2:4–7. Plaintiffs contend that 7 bifurcation “would significantly prejudice [Plaintiffs] by delaying resolution, increasing costs, and 8 allowing Simpson to engage in strategic gamesmanship.” Opp. at 10:17–19. 9 Here, the Court agrees with Simpson that holding a single jury trial would likely prejudice 10 Simpson. As discussed, bifurcation would result in fewer witnesses in the jury trial which would 11 almost certainly result in less cost for witness preparation and examination. See Mot. at 11:26– 12 12:4. And, as discussed, a single jury trial could result in Simpson wasting time and resources 13 arguing its invalidity theories to a jury that are later mooted by the determination on PGR 14 Estoppel. See id. at 12:4–6. 15 In making its determination, the Court must also consider prejudice to Plaintiffs. See 16 Houseman v. U.S. Aviation Underwriters, 171 F.3d 1117, 1121 (7th Cir. 1999) (“Next, the Court 17 must be satisfied that the decision to bifurcate does not unfairly prejudice the non-moving party.”) 18 (citing Angelo v. Armstrong World Indus., 11 F.3d 957, 964 (10th Cir. 1993)); see also Willemijn 19 Houdstermaatschaapij BV v. Apollo Computer Inc., 707 F. Supp. 1429, 1435 (D. Del. 1989) 20 (explaining in a patent case, “[p]erhaps the most important consideration for a court ruling on a 21 motion to bifurcate is whether separate trials would unduly prejudice the non-moving party”). 22 Plaintiffs argue that bifurcation would increase their litigation costs and increase the time in which 23 this matter would be resolved, which are valid concerns. Opp. at 6:27–7:9, 10:17–19; see 24 Transcon. Ins. Co. v. St. Paul Mercury Ins. Co., No. CV–05–31–H–DWM–CSO, 2006 WL 25 3859009, at *4 (D. Mont. Dec. 1, 2006) (“The risk of prejudice to Alpine does not outweigh the 26 delay, expense, and inconvenience that would result to St. Paul and the Court from bifurcation. 27 Bifurcation would require the Court, parties, attorneys, and many witnesses to go through two 1 The Court concludes that the risk of prejudice that would result to Plaintiffs from 2 bifurcation is minimal and does not outweigh the risk of prejudice that would result to Simpson 3 from a single jury trial. First, as discussed, it is difficult to envision how a shorter jury trial would 4 increase Plaintiffs’ costs, especially where there is no redundancy in witnesses and evidence. 5 Plaintiffs barely argue otherwise—they only state that they would have “to pay for certain witness 6 expenses twice.” Opp. at 11:9–10. But Plaintiffs’ brief is devoid of information showing that this 7 would be the case. Second, while bifurcation will result in some delay to resolution of the case, it 8 does not amount to “unfair delay” in this case because Simpson has demonstrated that other 9 factors weigh in favor of bifurcation. See Willemijn, 707 F. Supp. at 1435 (explaining “prejudice 10 under these circumstances may simply amount to unfair delay of the final disposition of the 11 matter” where moving party failed to show that separability, juror confusion, or judicial economy 12 factors favored bifurcation). Plaintiffs argue that they are prejudiced by delay because they filed 13 their initial infringement complaint six years ago. Opp. at 10:23–28. But “[p]atent litigation 14 frequently is complex, long, and difficult.” Rohm & Haas Co. v. Brotech Corp., 127 F.3d 1089, 15 1092 (Fed. Cir. 1997). While discovery procedures and summary judgment motions are often 16 necessary to narrow the issues for a patent trial, these add to the time spent litigating a patent. Id. 17 Such is the case here, where the parties have engaged in extensive discovery and litigated PGR 18 proceedings, dueling Daubert motions, and multiple summary judgment motions. In short, the 19 small delay caused by bifurcation does not unfairly prejudice Plaintiffs. Nor does Simpson’s 20 filing of its Motion “only three months before trial” prejudice Plaintiffs by “asking the Court to 21 deviate from an already impacted trial schedule with no good reason.” Opp. at 10:24–26. For 22 Simpson could only file its Motion after Plaintiffs moved for partial summary judgment on PGR 23 Estoppel and the Court issued its ruling on that motion. 24 Plaintiffs’ remaining argument that bifurcation “allow[s] Simpson to engage in strategic 25 gamesmanship” is unavailing. Id. at 10:19. Plaintiffs do not point to any improper litigation 26 conduct by Simpson or cite to any authority holding that a party’s sustained defense in litigation 27 bears negatively on this factor. Therefore, the Court disagrees with Plaintiffs that Simpson’s 1 Accordingly, the Court finds that this factor weighs in favor of bifurcation. 2 E. Juror Confusion 3 Simpson argues that “conducting a separate bench trial on the complicated issue of PGR 4 Estoppel reduces the risk of juror confusion and error, especially given the fact that the Court is 5 already well-versed in the complicated PGR Estoppel issues from the Parties’ earlier briefing and 6 the Court’s recent order.” Mot. at 1:28–2:3. Plaintiffs contend that this factor does not favor 7 bifurcation because “[t]here is no risk of juror confusion and error.” Opp. at 9:6–10:16. 8 Here, the Court concludes that bifurcation would reduce the risk of juror confusion. The 9 Court agrees with Simpson that bifurcation would reduce juror confusion by eliminating several 10 witnesses and multiple days of jury trial and removing “from the jury hours of complicated 11 testimony that will be interwoven with hours of testimony on other complicated patent issues not 12 related to PGR Estoppel.” Mot. at 10:28–11:3. Plaintiffs’ argument that there exists no risk of 13 jury confusion because “a jury is capable of comprehending [the] testimony and evidence” is 14 unpersuasive. Opp. at 9:6–22. PGR Estoppel involves complex topics, including multiple patent 15 classification systems, “the search string and search source that would identify the allegedly 16 unavailable prior art,” and expert testimony on “why such a criterion would be part of a skilled 17 searcher’s diligent search.” E.g., Ironburg Inventions Ltd. v. Valve Corp., No. C17-1182-TSZ, 18 2024 WL 2091177, at *4–6 (W.D. Wash. May 3, 2024) (in the context of IPR Estoppel) (cleaned 19 up); accord Asetek Danmark A/S v. CoolIT Sys. Inc., No. 19-cv-00410-EMC, 2019 WL 7589209, 20 at *8 (N.D. Cal. Dec. 30, 2019). This case is no exception—it involves extensive expert testimony 21 on patent subject matter classification, search tools, search strings, and Boolean searches. See 22 Columbia Insurance Co. v. Simpson Strong-Tie Company Inc., No. 19-cv-04683-TSH, 2025 WL 23 1635677, at *13–16 (N.D. Cal. June 9, 2025) (describing expert testimony on PGR Estoppel). 24 Further, Innovative Memory Sys., Inc. v. Micron Tech., Inc., cited to by Simpson, supports 25 the conclusion that the PGR Estoppel issue could lead to juror confusion. Mot. at 11:8–18; see 26 Innovative, 2022 WL 4548644, at *5 (“Sending that question [of whether the IPR petitioner 27 reasonably could have raised the ground during the IPR] to the jury would be contrary to one of 1 complicated trials by sending questions about the reasonableness of prior art searches to the 2 || jury.”); see also Valve Corp., 2024 WL 2091177, at *6 n.9 (citing Innovative with approval). 3 Plaintiffs are correct that the Innovative court held that there was no factual dispute on summary 4 || judgment regarding estoppel. Opp. at 10:10-14. But the court’s reasoning—that decisions on 5 factual disputes underlying IPR Estoppel are matters for the court because they would complicate 6 || trial for jurors—bolsters the conclusion that factual disputes underlying PGR Estoppel, which are 7 properly resolved in a bench trial, would needlessly complicate a jury trial. Innovative, 2022 WL 8 || 4548644, at *5. 9 Accordingly, the Court finds that this factor weighs in favor of bifurcation. 10 V. CONCLUSION 11 For the reasons stated above, the Court GRANTS Simpson’s Motion To Bifurcate. 12 IT IS SO ORDERED.

14 || Dated: August 21, 2025

LAA.

THOMAS S. HIXSON

= 16 United States Magistrate Judge

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