The first problem is your answer is condescending. To my reading your starting with probably some insider BS about what he's asking. He wants to know where he can find a capable or "rock star" developer. You interpret "Rock Star" as someone with bona fides of a whole different magnitude and then take the opportunity to bitch slap the guy in public. He's not thrilled and takes the opportunity provided to slap you back. There's not a lot of mystery here. Don't not answer questions in order to preen around in public by taking a shot at someones possible misuse of a term that might mean something different to an insider than someone trying to get in or in other words don't be an a-hole.
I am sincere. I think you could have handled this better by making the point you made and educating the person about your understanding of what a "rock star" developer is vs what you understood he needed in a less high handed manner.