I think she'd have to leave, if only because it was going to become an exclusively prosecuting set of chambers and there was no way she would conceivably be able to do that. She might well get out of the law, but I'm less certain about that.
I agree that the legal procedure is crap. There is absolutely no way the prosecution would have been allowed to introduce the evidence of either the gun or the coat without notifying the defence in advance and giving them the opportunity for full forensic tests.