What is the legal test for challenging a jury's impartiality with evidence of statements made outside the jury room?

challenge a jury's impartiality with evidence of statements made outside the jury room, if the statements are likely to have improperly influenced the verdict, but not with evidence to show the statements' actual effect, or the mental processes determining the verdict. (Ibid.) When faced with the possibility of a juror's misconduct, the court must first determine whether the information warrants any investigation into the issue, and "must take care not to conduct an investigation that is too cursory." (People v. Fuiava (2012) 53 Cal.4th 622, 710.) "After having completed an adequate (but not overly invasive) inquiry into the misconduct issue, the trial court must then decide whether, under section 1089, there is 'good cause' to excuse the juror at issue." (Ibid.)

Our review is "under the 'demonstrable reality' test." (People v. Fuiava, supra, 53 Cal.4th at p. 711.) We do not reweigh the evidence, but " 'must be confident the trial court's conclusion is manifestly supported by evidence on which the court actually relied. . . . [T]he reviewing panel will consider not just the evidence itself, but the record of reasons the court provides.' " (Id. at p. 712.)