His behavior is so erratic it's hard to know what his testimony will mean for his case. But he has a right to testify.
She has tried as hard and she can to get this difficult case right, and then she is confronted with a blatant violation of the rules. She has been careful and cautious, but probably is thinking about some kind of sanction.
All the survivors and families of people who perished on 9/11 will be called, and it's hard to imagine how to counter any of that.