McSorley was trying to goad him into a fight before the game ended, since at the time there was an automatic suspension for fighting after time expires. They fought earlier and Brashear had shown him up, flexing his biceps, dusting off his hands and generally making an ass of himself. Later in the 1st period, McSorley tried to get Brashear to fight him, but he wouldn't go, and McSorley got a 10 minute misconduct. With McSorley in the box, Brashear injured Byron Dafoe, his knee I believe, and knocked him out for the year. Later on he skated over to the Bruins bench and flexed his muscles. Classy.It's more the way he deliberately sneaked up behind him for the attack that makes it so dirty. Most other ones can use heat of the moment as an excuse. McSorely can't.
Burns sent him out to fight Brashear in the last minute. McSorley stated that he was trying to hook his shoulder, and you can see the stick slide up the arm into the helmet, it wasn't a direct chop to the head. McSorley was also playing with a bad left shoulder, which hurt his control of his stick.
McSorley had a 16 year NHL career, fought a lot of guys but didn't have the reputation of a Dale Hunter or Ulf Samuelsson for trying to injure guys. I find it unlikely that he would do that intentionally, though he's still responsible for his stick. Plus, I find it ironic that some Canucks fans, the team of Wayne Maki and Todd Bertuzzi, still loudly proclaim this as the worst incident ever.
This is a decent article from SI on the issue:
http://sportsillustrated.cnn.com/features/cover/news/2000/11/30/mcsorley_yir/