That wasn't even boarding.
I've seen Penguins get hit into the boards with no call (McDonaugh on Dupuis last Saturday for example)
I will never understand how people say the Penguins are favored by the referees. How many times have teams had the chance to hack away at a loose puck in the crease when replay shows it's not in clear view? How many BS penalties have been called on the Penguins? Look at the Flyers games. How many times has Couturier cross checked Malkin before he retaliated? Who gets the penalty? Malkin. One of the Flyers flipped the puck down the ice for Hartnell, it's offsides but takes a shot on Fleury anways. Not even 30 seconds later, Bryzgalov covers the puck and Neal tries to get the puck .8 seconds after the whistle and gets a penalty.
I don't think the refs are against us, I just don't think they help us like so many people seem to believe.