At the time of writing, the final score is still listed as 4-3 on the official NHL website, but that's an error.
Where it becomes significant is in the realm of sports betting. Wagers on sports, including hockey, are extremely popular, and there are always categories for betting on which team wins by a certain number of goals.
Imagine all the bets that are affected by this error. All the winners who aren't really winners and the losers who become winners. It's a real puzzle to solve, and it's happening everywhere on the internet.