This is an old vid of mine, but it's still a classic. It's from the Buru the Gorger encounter in AQ-20.
We discovered an obnoxious bug one day, that caused him to glitch whenever one of the players he was chasing would lead him up this big hill in his area. (The encounter requires whoever he's targeting to run like hell, you don't actually tank him until he's under 20%)
Basically, he would stop running, lean over the hill, facing down, then teleport a random member of the raid to him, which would cause said player to fall and take falling damage. He would then teleport that player to him again, causing them to take additional falling damage and repeated this until they died. He wiped out half or more of the raid doing this. I missed recording it the first time, but I had fraps ready when he did it again later.