What is the test for excusal of a juror who is "intimidated" by other jurors?

inability to perform as a juror must be shown as a 'demonstrable reality' [citation], which requires a 'stronger evidentiary showing than mere substantial evidence.' [Citation.]" (People v. Wilson (2008) 44 Cal.4th 758, 821.)

In People v. Warren (1986) 176 Cal.App.3d 324 (Warren), after the case had been submitted to the jury, a juror told the trial court "that she had been 'intimidated' by the other jurors, that she was in disagreement with them, that she felt she was going to 'break under it,' that 'I feel so intimidated now that I think I would vote the way the group wants to vote even though I firmly believe I shouldn't,' and that 'at this stage I'm afraid that I will give in and maybe I won't.' " (Id. at p. 326.) She said she could not follow the court's instruction that she should not be influenced to decide any question in a particular way because a majority of the jurors or any of them favor such a decision. (Ibid.) The appellate court found no abuse of discretion in the excusal of this juror. (Id. at p. 327.)