Orange Cnty. Water Dist. v. Arnold Eng'g Co.

*102 The Orange County Water District (the District) appeals a postjudgment order awarding The Arnold Engineering Company (Arnold) approximately $615,000 in costs of proof under Code of Civil Procedure section 2033.420 based on the District's failure to admit certain fact-specific requests for admission (RFAs) during discovery. 1 The District contends the trial court erred in making the award because (1) the District had reasonable grounds to believe it would prevail on the matters at issue under *103 *356 section 2033.420, subdivision (b)(3), and (2) even if it did not, Arnold did not adequately substantiate its costs with admissible evidence.

We conclude the court abused its discretion in awarding costs for certain RFAs because the District reasonably relied on percipient witness testimony, undisputed scientific testing, and the opinions of a qualified expert in denying the RFAs. The court did not err with respect to other RFAs, which covered matters the District did not pursue at trial. We further conclude that certain evidence, in the form of expert witness invoices, was inadequate to support an award under the circumstances here because it did not distinguish between…