1 2 3 4 5 6 UNITED STATES DISTRICT COURT 7

NORTHERN DISTRICT OF CALIFORNIA

8

9

10 ECO ELECTRICAL SYSTEMS, LLC, 11 Plaintiff, No. C 20-00444 WHA

12 v.

13 RELIAGUARD INC., et al., MEMORANDUM OPINION ON

SUPPLEMENTATION

14 Defendants.

15 16 Supplementation under FRCP 26(e) is designed to allow parties to correct mistakes and 17 misleading omissions in previously submitted disclosures and responses. It is not a new 18 opportunity to submit a completely revamped expert report. See Avila v. Willits Env’t 19 Remediation Tr., 633 F.3d 828, 836 (9th Cir. 2011). Rule 26(e) “does not give license to 20 sandbag one’s opponent with claims and issues which should have been included in the expert 21 witness’ report (indeed, the lawsuit from the outset),” and allowing supplementary reports to 22 preliminary reports means “there would be no finality to expert reports.” Mariscal v. Graco, 23 Inc., 52 F. Supp. 3d 973, 983–84 (N.D. Cal. 2014) (Judge Thelton E. Henderson) (citation 24 omitted). This is why the case management order delineated the process through which all 25 expert issues may be vetted by both sides or be precluded, a system that has worked well for 26 the undersigned over the past 23 years (Dkt. No. 63 ¶¶ 3–5). “Courts set such schedules to 27 permit the court and the parties to deal with cases in a thorough and orderly manner, and they 1 must be allowed to enforce them, unless there are good reasons not to.” Wong v. Regents of 2 the Univ. of Cal., 379 F.3d 1097, 1105 (9th Cir. 2004). 3 Proper supplementation includes replacing damages estimates with real data that 4 becomes available only after the expert report was served. In our case, plaintiff's damages 5 expert originally made an estimate of sales for PG&E’s use during the remainder of 2021 and 6 all of 2022. This was because the report was done in 2021 and an estimate was necessary. 7 Now that 2022 has come and gone, those estimates can and should be replaced or 8 “supplemented” with the actual sales data. Supplementation, however, in no way includes 9 adding yet more damages periods not previously calculated. Therefore, all additional periods 10 shall be stricken from plaintiff’s damages report. Plaintiff must update for 2021 and 2022 to 11 use the real data. This should be the only change. 12 If plaintiff wishes to enlarge the damages period, a formal motion will be required.

IT IS SO ORDERED.

a 16 Dated: March 14, 2023.

18 [A = I bem

WILLIAM ALSUP

19 UNITED STATES DISTRICT JUDGE 20 21 22 23 24 25 26 27 28