I'm sure most will tell me to Lighten up francis and perhaps I should
but it bothers me when company representatives insult me because of my choice of sports team. I shouldn't have to feel defensive while I'm patronizing someone's business. Ever. I'm sure it goes against whatever list of core values they espouse and if a manager was nearby, would likely result in at least a rebuke if not more.
It's a petty act by a small person but to do so while representing someone's employer is myopic and foolish.