Matt Niskanen has been suspended one game for his cross-check to Brendan Gallagher's face during Game 5 on Wednesday. This is no doubt a light suspension if you consider that the time that Gallagher would likely be out. However, I've heard that one game in the playoffs is considered to be worth at least two in the regular season. By issuing the suspension, the NHL is at least acknowledging that this wasn't a hockey play. So it's better than nothing.
You've probably seen the damage to Gallagher by now, but if not and you're okay with some blood, you can watch it here. Gallagher has a broken jaw, so he will miss the rest of the series against the Flyers, however long it will last. Even if the Habs win two straight and get past the Flyers, it's quite possible that we've seen the last of Gallagher in these playoffs anyway.
I know that a team's coach will defend his player during a critical point of a playoff series. Yet check out the spin below from Alain Vigneault regarding his player's actions. I'm not a doctor and I don't even play one on this website, but getting cut a little bit is vastly different from a fractured jaw. It might be gamesmanship, but I'm sure Vigneault will want to take this statement back later. Gallagher's teammates might turn around and use it as extra motivation, though.