Its both frustrating and appeasing the way one can behaive. I suppose it was too much for the cop to shake her hand, but at the same time, he was professional enough to do his duty.
It shouldnt make you cringe, just remember that some are more accepting than others. And while we may want everyones acceptance and understanding, we arent going to get it. I would simply be happy that regardless of his(the cop's) personal feelings, it didnt stop him from doing what was right.
Can't please everyone all the time I suppose.