What is the test for misconduct in a trial where a prosecutor accused defense counsel of "disingenuous" and "lawyer speak for lying to you"?

The People effectively concede that the prosecutor exceeded the bounds of permissible vigor when he accused defense counsel of making a "disingenuous" argument, which he defined as "lawyer speak for lying to you," and implying that defense counsel violated "an obligation not to argue things we know to be false to you." (See People v. Young, supra, 34 Cal.4th at p. 1193 ["We agree that to the extent the prosecutor characterized defense counsel as 'liars' or accused counsel of lying to the jury, the prosecutor's remarks constituted misconduct"].) We accept the People's concession, and conclude the comments were harmless. The comments were made in response to defense counsel's argument that the prosecutor presented evidence of defendant's jailhouse conversations in an underhanded and deceptive manner, which the prosecutor reasonably interpreted as a personal affront. Although the prosecutor should not have engaged defense counsel in a tit for tat exchange of insults, "[i]t is reasonably likely that the jurors viewed the prosecutor's remarks as mere reciprocal retort" to a defense attack on the prosecutor, "and gave it little to no consideration." (Ibid.)