that witness is cohen. cohen may be lying. at that point, the perjury trap has been sprung and mueller could theoretically charge him with pernjury for telling the truth. so you never advice a client to answer a question truthfully if there is another person who will answer the question differently and that person may be believed by the prosecutor and that is what we mean by a perjury trap. >> does that seem viable? first, you're referencing michael cohen who said there were other people present in the room. if there's not actual documentation, why would the prosecution decide to side with michael cohen who has lied about other stuff? >> well, first of all, we don't know first of all whether michael cohen has been interviewed in any way. using michael cohen as an example doesn't comport with using someone interviewed under oath or in front of