When I was a kid I saw the guitar player from Coal Chamber come up behind the promoter while he was talking to the audience and push him off the stage. It was like a 5 or 6 foot drop onto concrete. The best part of that show was that Coal Chamber didn't play.
They also gave back our tickets so we could get a refund. I got two tickets and ended up being paid for the privilege of witnessing an epic travesty of a concert.
The Oh Sees (though I believe this was the Hospitals - same main guy though) are pretty great, not that you could tell from this video. To put the video into context, the Hospitals started playing on the floor because the local opener went on late and were playing too long.
Dan Burke is a legendary/notorious promoter in Toronto. Loved and loathed in that scene. From what I know about him I wouldn't call him a bad guy but I will say his battle with chemicals seems to make diplomacy impossible at times.