I run 9:30 miles too, and I actually have a boss (nice one thankfully) who actually does run 6 minute miles. He does look the part though. Very thin.
Anyway, I would like to suggest that even though this guy might be a blowhard and an idiot, it sounds like he's at least somewhat in charge and you have only worked there six weeks. Who do you think is going to win that battle in the end? You don't get to choose who you work with. You don't have to like them. But you do have to be professional if you want to stay with the job. Just saying...