Annoying bug with Ogre Mages

It happened quite a few times, when fighting an Ogre Mage, they will bug in their "gazous" form and become unresponsive. Many times, it won't be a problem, but in some particular quests, it's a much bigger problem. It happened yesterday in the quest: The Spawn of Whisperdoom. In this quest, killing the 7 Ogre Mages is mandatory to advance to the next part and boss fight because they guard a sealed door. I had to recall and restart the quest 3 times because one of these ogres would bug and become unresponsive, making the quest impossible to be completed.

The last time I tried the quest, I was crossing my fingers every time hoping they wouldn't bug out. I even had it in my LFM: "Elite BB IP, Last try, hoping the ogre mages won't bug again". This happened also in the Twilight Forge explorer area where 2 normal ogres, and 2 ogre mages need to be killed to get a door opened, on the way to Ghola Fan. The only thing to do was to reset the instance. This happened mostly with my warlock because that's the character I'm currently level up.

_{Happens with warlocks in group :D}

The Warlock ES aura is kind of wonky in its interaction with scripted kills. I suggest turning off your aura in fights like that. I had a similar issue in shadow crypt and the problem was reproducible.
Also, killing the wizard too fast sometimes seems to bug that quest.

Yeah, I've had issues with warlock (I believe it was the aura, though it's possible that it was the bursts) bugging out quests mobs. For me it was in Shadow Crypt.