Why did Duncan Keith slash Charlie Coyle

There isn't any excuse for Duncan Keith's slash on Minnesota Wild's Charlie Coyle, but what really pushed him over the edge?

The Blackhawks' defenceman got a 5-minute major and a 10-minute game misconduct for his vicious slash. He underwent a phone-hearing with the NHL department player & safety and received a 6 game suspension (last 5 season games and Game 1 of the Stanley Cup Playoffs.)

But is Charlie Coyle really that innocent in the end?

Seconds prior to the incident, Coyle is seen getting at Keith's face with a cross-check and then slamming him to the ice.

Coyle told reporters there is no place in the game for Keith's slash.

I was just stunned that it happened. You don't expect that ever in a game, Coyle said. No matter what happens in a game you should never swing your stick at someone's face like that. There's no room for that, and I'm sure he [Keith] wants to take that back. Heat of the moment thing... that's how it happened.

There wasn't a penalty called on Coyle for the Cross-Check or the slam to the ice. Do you think Coyle should have a hearing for his part of the play? But then again Keith's slash was a careless act.