I really don't see how this is such a big issue, it's slightly out of place to call someone sexy, but the simple fact of the matter is that it is partially just a matter of gender associated terms. Imagine this:

> "Robert's one of the smartest men[1] I know, and I thought that he was a perfect pick for the role of moderator. When we selected Robert and he said yes, he was a handsome single man. And since that time, he’s become a handsome married man, and so I wanted his lucky new spouse to stand up. So we’ve got not only a very talented, but a happy moderator."

That doesn't seem even remotely odd or out of place to me (perhaps it would be as the entirety of an introduction, but that isn't the case here). So yes, he maybe should have said "beautiful" instead of "sexy", but if people think this is an example of how the tech community is sexist then they are seriously deluding themselves with how non-sexist it really is.