Is this a red flag or am I exaggerating?

I'm currently getting to know a man through friends. We first met in December, and so far, I've always thought of him as very nice. However, at the last friends' meeting, I noticed something that slightly turned me off.

I'm not sure if it's just friendly fun and I'm overreacting (I've been extremely cautious about new acquaintances from the start; it could be self-protection), but whenever one of the friends made a mistake, like knocking over a glass or not understanding something, he would sometimes suddenly get loud and yell things like, "Are you stupid?" and "How stupid can you be?" He always smiled a little, though, and the people involved at least didn't seem to take it seriously. So, of course, it could really have just been fun, albeit pretty intense fun. But every friendship is different. I've acted clumsy at times during our meetings, but he hasn't said anything like that to me. Probably because we don't know each other that well yet and the inhibition threshold is higher. But who knows how things will play out once we're more familiar with each other… personally, that kind of communication would bother me. Otherwise, he seems really nice.

Would you stay away or am I exaggerating?