I was not there, but had it described to me and I saw a video on a small cell phone screen--hard to tell much from that. But as it was described to me the player was on a rush to the net, and as he got there he was bumped/taken down from behind in/around the crease. Definitely questionable, but something that happens a dozens of times in a game. The player took exception to the takedown and got up using his stick on the opposing player. Hard to see in the small video I saw, but others said he used the butt of the stick and was jamming it into the opposing players neck repeatedly. A heated scrum ensued....
