Well the thing is, he's probably not going to preach a retraction.
So, what are you hoping to accomplish? It can't be unsaid. He's not going to track down everyone there and tell them actually he was mistaken. You'd be lucky if he *admits* he was mistaken, frankly.
Mostly, I expect, what you want to accomplish is that he stops, thinks about it, checks his ideas, and then *in the future* maybe doesn't say that. But for this time? There's nothing to be done about it.
So whatever you decide to do, remember that you are trying to win him over so that next time doesn't happen. Going in with guns blazing to tell him he's wrong probably won't accomplish that, you know? Keep your end view in mind.