I'm inclined to think it's a bug. I went back to a save just prior to the event and can't reproduce it.
I'm willing to provide the save a little bit before the fight, when I was already in the ceremoial place, and a save after the fight (and having looting the corpses), for study, but I don't know how I can upload them.
I can't find Kagha's body either. I know she died, because Gale had linked to her with his lightning bolt from quite a distance while she was in melee with a tiefling. And while she was thus occupied, she got a tickling from him every turn until she went down.
