Raiders of the Lost Rock glitch

Killed King Gnasher with Moze (at least I think I killed him), but the kill apparently did not register (he was trying to escape my Bear attacks at the time). Tried throwing area of effect grenades where I last saw him. Tried fast traveling away and running back. Nothing. Had to quit to main menu and restart. Then King Gnasher showed up again and I killed him clean. FYI.