What is the test for determining whether prejudice was prejudice against a defendant in a civil case?

historical fact if supported by substantial evidence. [Citations.] Whether prejudice arose from juror misconduct, however, is a mixed question of law and fact subject to an appellate court's independent determination." (People v. Nesler (1997) 16 Cal.4th 561, 582 (Nesler).)¹⁹

Before directly addressing defendant's appellate claims, we point out that the trial court could rationally reject all of the facts stated in the supporting declarations. "Provided the trier of the facts does not act arbitrarily, he may reject in toto the testimony of a witness, even though the witness is uncontradicted." (Hicks v. Reis (1943) 21 Cal.2d 654, 659-660.)