It's funny how you say "A bunch of people who killed him said it's not bugged." and use that as evidence that those who say it is just find it unfair that they can't get it down/that they're somehow not skilled enough. So wait, if you can apply the argument that their claims of a bugged fight are because they can't down it, I can also apply the argument that, because people got it down, their burst of victory make them happy and prideful enough to say that it was their own skill that got it down, not good RNG.
After which we can move over to more useful information.
When a mob stops and keeps standing in a pool that buffs it (which is inevitably your death at any amount) when you're quite a few yards away from it, then that's not player fault; that's faulty encounter mechanics at work. And that, together with where he tends to drop his bolts made me tweet Watcher and tell him to check Nibbleh and Anthracite out, if not all of the encounters. You'll probably dismiss the claims as "the people I was with are more reliable than the people who are with you, as well as WoWhead." again. Your anecdotal information somehow being superior to mine for whatever reason, but I don't care, really.
For the record, I find you dismissing such complaints simply with a "Eh! They're just butthurt that they can't get it down!", and henceforth sticking your metaphorical fingers into your metaphorical ears and going "LA LA LA LA! The fight can't be bugged or flawed design-wise in any way! Just whiners gonna whine!" very disrespectful, but what did I expect, really?