What is the current state of the law on "were they lying" questions?

We disagree that there was any misconduct here. "Were they lying" questions must be examined in context. (People v. Chatman (2006) 38 Cal.4th 344, 384.) "A defendant who is a percipient witness to the events at issue has personal knowledge whether other witnesses who describe those events are testifying truthfully and accurately. As a result, he might also be able to provide insight on whether witnesses whose testimony differs from his own are intentionally lying or are merely mistaken. When... the defendant knows the other witnesses well, he might know of reasons those witnesses might lie. Any of this testimony could be relevant to the credibility of both the defendant and the other witnesses." (Id. at p. 382.) Consequently, "were they lying" questions "should not be permitted when argumentative, or when designed to elicit testimony that is irrelevant or speculative. However, in its discretion, a court may permit such questions if the witness to whom they are addressed has personal knowledge that allows him to provide competent testimony that may legitimately assist the trier of fact in resolving credibility questions." (Id. at p. 384.)