My experience with the molag bal quest was pretty lame, I'm re-doing the quest right now but seriously. First, I got his hp to 0 but nothing happened
Then I fell through the map and tried /stuck and relogging, in the end I had to forcefully close the game
Once I relogged (after like 3 failed attempts) I got the whole scene with Molag Bal and the "sacrifice of courage" thingy again, but then Molag Bal was just standing there with full hp next to me, and I couldn't attack him or get him to attack me
So that's it, and now I'm redoing the whole thing after teleporting out of Coldharbour and hope it'll work.