ToME: the Tales of Maj'Eyal

I hit the boss in the ambush with Rune of the Rift and "died" a few turns later. I got the free revive and quest update as usual, then a turn later the boss returned. No errors, though, and the exit did appear.

That's weird, I've used the same rune on him and that hasn't happened, but that was back in b32 and b33 when I had characters make it to the east.