Bertuzzi charged with assault

Vancouver Canuck strongman Todd Bertuzzi has been charged with assault for his on-ice attack on Colorado Avalanche forward Steve Moore in March. As you may recall, Bertuzzi sucker punched Moore in the back of the head, and Moore landed on the ice face-first with the weight of Bertuzzi and other players atop him. Moore is still in recovery. Bertuzzi was suspended for the remainder of the season, and the NHL will decide later whether he will be allowed to play again.

I can sympathize with the NHL's position that no charges were necessary, but this was a pretty vicious (and gratuitous) attack, so it's hard to fault criminal charges. What do you think: Should what happens on the ice stay on the ice, or did the Bertuzzi attack cross the line of what constitutes a criminal act?