Nathan Beaulieu should have had a phone call with the Department of Player Safety. He should probably be be sitting for at least one game, and that likely would have been the best route for the NHL.
Beaulieu's cross-check the neck area of Zac Rinaldo was clearly against the rules, and the rules do not provide for a reprieve when you're hitting a traditionally predatory player. The rule book should applied to all players, the same way, regardless of the situation.
That being said, while the act was certainly suspendable, given who was coming at him, he could have been acting in self defense.