After the goal-ahead goal, a rowdy Boston crowd was banging on the glass to celebrate, and it shook a pane of glass loose that fell on the elderly NHL official working the penalty box.
The man's name is Joe Foley, and he's an off-ice official for the National Hockey League as a penalty box attendee. After the incident, trainers were brought over to attend to Foley, who would eventually have to be stretchered off the ice in a scary scene.