In the final battle with the voidwoken drillworm, my friend and I fled battle when only the worm and the elementalist were still alive. We came back and it looked like the worm had killed the elementalist (which is fine), but when we went to fight the worm it did not react to us. It just sat there for 8 turns or so as we pummeled it til it died.
Also, I don't know if this is a bug or intended, but the "permanent" blood rose potion effects have disappeared from two of our characters. It may have happened after they died and were resurrected--I'm not sure.