While on the penalty kill, David Kampf won a battle along the boards and chipped the puck to Mitch Marner who was in on a breakaway but felt pressure from Alex Tuch. The pressure led to Marner dropping the puck back to Mark Giordano, who was not expecting it, but just as he was shovelling the puck towards the net, Tuch crashed into it and knocked it off it's moorings.
Initially, Tuch was given a delay of game penalty, but after review, the league decided that because there was an "imminent scoring chance" and that the puck crossed the line within where the net would be, it was deemed a good goal. It was surprising the Sabres didn't challenge the play as the replays shown on TV didn't clearly show white ice between the puck and goal line, even if the line that the puck was taking likely would have seen the puck bump off the post and in.
