Update 2: The NHL has suspended Andrew Shaw 1 game for using gay slur.
Update 1: Shaw has now admitted using and apologized for the slur.
Original article:
Andrew Shaw of the Chicago Blackhawks picked up a critical penalty late in his team's 4-3 loss to the St. Louis Blues on Tuesday. He was caught on camera in the penalty box uttering what appears to be a gay slur.

It's clear that he says "fucking" and "fuck you" and also appears that he inserts "faggot" after fucking. After the game, Shaw says he doesn't remember what he said. "Emotions were high. I don't know what I said. I wasn't happy with the call."
One Outsports reader commented: "I'm not gay but I'm a lip reader because I have hearing loss. I can tell it's definitely faggot."

Fans on Twitter are convinced he used a gay slur. A video below implies he used it right after getting a penalty:

In addition, Shaw flipped a double bird, apparently in the direction of the referees. He will likely get suspended for that alone, but the possible use of the slur needs to be investigated.