it is if its the only thing you're looking for it but if you're not then there are countless possibilities. One of which being that he'd read up on her work, was excited about it and blurted it out accidentally instead of letting her talk about it.

If there was a second woman on the panel then we'd have greater clarity about making the assertion if he behaved the same way. Sadly there wasn't which means that we should be cautious about labelling it as out and out sexism.