V 1.2.5.312
A target follower for a quest is sacrificed, the quest did not resolve
A follower asked me to sacrifice another follower, so I figured I'd get two birds with one stone and gave the victim the Light Amulet. However, this did not resolve the quest to kill said follower.
I probably could reproduce the bug on another save file if I tried. Alas, I don't have another late-/post-game save file at hand.