So...I was going to respond to a bunch of posts but there were just too many.
Just to clear a few things up:
1. A witness being impeached is not an EVENT that causes anything else to happen. It just means the cross-examination went well.
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
It does not mean there is some announcement to ignore her testimony. It does not mean there could be a mistrial.
2. Witnesses lying on the stand is also common and normal and a daily occurrence. This does not cause a mistrial or create any need for a separate hearing. In the EXTREMELY unlikely event that perjury charges were brought--and I mean close to zero percent probability--those charges would be brought in a separate criminal proceeding and not as part of the proceeding in which the witness was testifying.
2. If JM had wanted to disqualify ALV as an expert, that motion would have been made and ruled upon before she got on the stand. And absolutely nothing she has said on the stand has altered the qualifications JM was aware of before she got there. And she clearly is qualified as a DV expert anyway.
3. There is some possibility that this hearing on Tuesday will concern ALV's approach of Samantha, depending on what she said and what she had been instructed prior to that time. Obviously, she knows at least as of today that it would be illegal for her to approach the family for an interview. It would also have been illegal for her to approach the family as an agent of the defense team (e.g., bearing a message from the defense), rather than going through the prosecutor. It would not have been illegal for her to say, e.g., "sorry, nothing personal" to Samantha, although it would have been unprofessional and thoughtless. But perhaps somehow she had already been instructed not to talk to the family? Seems unlikely, though. Anyway, my guess is that the hearing Tuesday is something about ALV that has ticked off the judge and that ALV was subpoenaed for (so she is not testifying in her expert capacity IMO). I suppose there is also some possibility it's a contempt hearing relating to her non-cooperativeness on the stand, since she was admonished numerous times and might have been further instructed in chambers. But normally non-cooperative witnesses are not held in contempt--they are just made to look like biased fools in front of the jury, and that's good enough for most of us.