Looking at the article a little closer, I think I see that the male professor has a lawsuit he can file before long.
The International Studies Association is just another academic organization. It has no power, nor standing, to punish the professor for what he said. Free speech prevails. There is no employment relationship whatsoever. These kinds of organizations are really powerless, thank God!
He is probably counting how much money he wants to sue ISA, the female professor, and her host institution for infringing on his First Amendment rights.
Whether or not we agree with sexual harassment, it is really an artifact of employment law. It has no power whatsoever “on the street.” The First Amendment lives!
The guy is from Kings college in London so I don’t even know how much weight this will have over there. The British academia ,in general, still seems to have more humor.