What is the test for a jury to determine whether misconduct occurred?

"On review from a trial court's 'determin[ation of] whether [juror] misconduct occurred, "[w]e accept the trial court's credibility determinations and findings on questions of historical fact if supported by substantial evidence." ' " (Barboni v. Tuomi (2012) 210 Cal.App.4th 340, 345.) If misconduct occurred, a presumption of prejudice arises that may be rebutted by evidence that no prejudice resulted. (Iwekaogwu v. City of Los Angeles (1999) 75 Cal.App.4th 803, 818.) We review "the entire record, including the evidence, and make[] an independent determination as to whether the misconduct was prejudicial." (Barboni v. Tuomi, supra, at p. 345.)