i'm not saying you're a bad person or generally an asshole, there's a world where i might have done the same thing, it happens. but there are ways to communicate that you think it's a stupid strat without literally saying "that's fucking stupid" and presenting the tone of "your win is meaningless and i don't care".

to me, this looks like you two had different ideas about what your relationship was, where he maybe thought you were closer than you were, and he excitedly made some banter about beating people he seems to lose to over and over. i don't think this was some sadistic machiavellian ploy, probably just a dude excited to grab a win at his local and hang out with his friends, and from that angle your response seems pretty uncalled for, or something you say to a stranger you don't like.

with all that said, was he perhaps too sensitive and overreacted? yeah, maybe. but it's also entirely fair that maybe he realized you weren't his friend in the way he thought you were, or that he doesn't want to be friends with someone who makes him feel bad, and that's okay.