At 2:24 of the first period, with the puck in Montreal’s end, Paul Byron and MacKenzie Weegar dropped their gloves at the blue line. Byron took a punch square, and crumpled to the ice, needing to be helped off to the dressing room rather than serving his major penalty in the box.
It’s therefore no surprise that the team announced he would not be returning for the rest of the night.
Byron had been suspended earlier in the season for a high hit on Weegar, and despite receiving discipline from the league, Weegar apparently believed he had some personal justice to dole out.