I ran this raid every single week from the date it was released until the Rohan expansion launched a year later. In all that time, I had it bug out 2-3 times total. This was not a static group, although most of us would play together often. Other than that, we had new people in and out week after week. And the only time we ever had anti-exploit trouble was when people were trying to do things against the intentional design of the instance (tanking the head without taking damage, for example).
I don't say this to discredit those who do have troubles with it. I have no doubt that there are people that constantly have the instance bug out on them. I say it because every time I hear about Draigoch bugging out, I wonder what it is that the group is doing that I did differently. Why do some have such trouble with Draigoch bugging out, while others such as myself can run it 50 times straight and never have a single problem.
I've heard a lot of rumors as to why the instance might bug out. There was only one that held any weight, and I think it actually confirmed by a Dev on the forums at one point, although I might be wrong about that. I don't remember the exact specifics, but it had something to do with a combination of a Loremaster skill or buff and a Burglar skill. Perhaps someone else with more knowledge can help confirm or verify the thread for me.
So my advice? If you don't want it to bug, don't bring a Loremaster. If you have to have one, inform the Loremaster only to use attacks and/or contribute to FMs. Steer clear of buffs like Wind Lore, or attacks like Sticky Gourd (I can't out why, but Sticky Gourd for some reason sticks out in my mind as being the potential cause of this bug). Of course, this might not be the reason for it bugging at all, but it's always the one that I thought sounded like the genuine cause of the bug.
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