Nope. There were many people around, and it was clear that he didn’t know all of them. There were people he didn't know just as close as I was. He apologized only to me, nobody else.

Thanks for the clarification. If you don't mind sharing more and if you remember, what was the exact usage of the word? It seems like some of them could be construed as sexist, as I referred to in another comment. So maybe that was why he was apologizing. I assume you didn't think it was sexist (or you would have said so), but maybe he was concerned it could be interpreted that way.

(If that's the case, he shouldn't have said it regardless of who was around, but once he said it, apologizing with some amount of sincerity would be better than not apologizing.)

It's been years but I think it was just exclamation. Like "oh, fuck!".