That's a good question. I think that trial went about as well as the defense could have hoped, so I doubt they'd want to risk another one. I wish they'd objected when BDLR made the statement. The sidebar would have thrown BDLR off, I think. Perhaps they could have gotten a curative instruction that would put BDLR in an embarrassing position, and would let the jurors know something was hidden from them. I'm quite curious to see if the defense makes it an issue.
The state took overnight to object to Serino's statement that he thought Zimmerman was telling the truth, and the state got a curative instruction. That remedy is certainly less invasive than asking for a mistrial.
I think it would be a good thing to ask for. If Nelson denies it, one more issue for appeal. If she grants it, puts the state in a rather embarrassing position. OTOH, it would make an issue of absence of evidence of fighting. I'm not sure the jurors would figure it out, but absence of evidence of TM fighting ability was a court decision (to keep something hidden from the jury), and a contentious one at that, decided just yesterday.