Grim(oire) Business is bugged?

I see alot of people getting the Fa-la-la-la-Ogri'la achievement on Lordaeron, but I can't really get to bomb them again quest because the grimoire doesn't drop to me when I kill ogre on Grim(oire) Business. Is it bugged? all those people done this quest before it got bugged?

I saw the bug report on bugtracker, but almost no upvotes in comparison to the other Winter Veil achievements bugs, so can I assume everyone got the quest to work for them somehow?


Edit: Alright, on my ~20th try I got it to drop.
If I removed molten shield and stopped using dots/spells completely and did the last blow with auto attack when he has no debuffs it dropped.