We don't know how the comment was made. It might have been a joke, albeit a very poorly timed and worded one. Remember, we're dealing with academics here. They're not exactly known for their senses of humor.
I'd be willing to bet $100.00 that professor won't EVER tell him or any player "good game" even when they win. He needs to be called on the carpet for that! Especially saying it in front of the students in that class.