The Bruins, down 3-0 in the third, achieved a compact and miraculous comeback. They scored twice in the final 90 seconds after pulling their goalie, and salvaged an extremely unlikely comeback. (The Rangers would win in the shootout.) But in the game-tying goal, a rebound right to Brad Marchand that he put top shelf, was a moment of celebration at the TD Garden. Nowhere more so than in the NESN broadcast booth.
Jack Edwards's homerism is a tricky thing. He's not as obnoxious about it as Hawk Harrlson. (Canadiens fans would beg to differ.) He hasn't yet slid into self-parody. (Flyers fans would beg to differ.)
But most broadcasters go into the industry initially because they're fans, and if their passion isn't beaten out of them by the job, they're still jumping for joy internally when their team succeeds. Most are just able and willing to hide it, is all. So the answer to Jack Edwards's homerism is this: he's only insufferable when Boston is playing your team, or the Bruins are doing well. Which, these days, is all the time.
Your Jumpin' Jack Edwards gif, via NESN.com: