As I heard it, the tradition is that if a team member returns to play against their old team, he pins some cash to the bulletin board, and whoever gets the winning goal against that team (supposing they win) gets the cash.
In this case, it was the coach (Ron Wilson) playing against his old team (the Sharks). Ron put up $600 (i heard, because if they won, it would have been his 600th win). Gunnerson potted the winning goal and therefore got the money - which he said he will spend on a team dinner.
Apparently this violates the cap rules and the collective agreement prompting the fine:
The Spin
It may have been only $600. But it was $600 too much.
The NHL has informed the Maple Leafs they will be fined an undisclosed amount for violating the league's salary cap rules after head coach Ron Wilson rewarded his players with a small cash bonus after winning his 600th game in San Jose on Tuesday.
"We have no problem with this fine," GM Brian Burke told The Star today. "Ron wasn't aware this conduct is not permitted, nor was I. We accept the fine without objection or protest of any kind."
Part of the cap system instituted in 2005 was intended to make sure there were no more side deals between teams and players that were not specifically part of the Standard Player Contract. Teams used to routinely keep unofficial agreements "in the drawer" that allowed players benefits, cash or otherwise, that the league never knew about.
Article 26 of the current collective bargaining agreement states clearly "Neither a Club nor a Club Actor may pay or provide a Player anything of value except as provided in his (contract)."
Obviously, Wilson's cash-for-wins move isn't a violation on the same level as that committed by the New Jersey Devils with the Ilya Kovalchuk situation last summer, and it was a small amount. At the same time, if GMs and coaches were to start blatantly giving thousands of dollars in cash incentives to their players it would be a way for teams to get around the cap.
That said, it happens. At least one NHL manager put $100,000 of his own money out for his players if they could knock off a rival in a big playoff series several years ago, and nobody ever heard about that.
What the Leafs were most guilty of, quite probably, is making it too obvious, with Wilson caught on camera with a wad of cash in his hand after the 4-2 victory and with players openly commenting on the matter.
The moral of the story is probably that if you're going to violate the cap, do it quietly.