Is this a bug, or did they change the way it works?
I was in Druid's Curse on Heroic Casual (farming commendations). I got to the end fight, and as the fight was winding down, I ended up fighting Halsaime in both his human for and his giant dire bear form at the same time. Even after his human form died and the quest completed, I was still fighting the bear form. And it was regenerating even though none of his minions were left.
On the run before that, in the end fight, I killed Halsaime in his human form and finished the quest before he ever got to the bear form.
I'm assuming it's messed up, but you never know.