I think I found a weird bug in tb - I was running the JMMW team on kessel (jmmw, jocasta, Dep, jtg, Kelleran Beq) - JMMW got reduced to red health from combat, looked like he stopped at 1 hp instead of dying.
Then jocasta triggered her bonus turn (from 100% health and like 80% protection), did her AOE and defeated herself.
She wasn't targeted in the sequence before and was under stealth, so it seems like the leader being reduced to 1hp incorrectly triggered her bonus turn