When I go to to other teams stadiums I act respectful because I know it can get hostile. Boston is no exception. Try going to a Red Sox game in a yankee hat as a black man.
I can try the hat but the black part may be a little tough.
In all seriousness though, I have been to many pats games and I've never seen anything like that after a game. There is so much security that nothing like that fight could ever take place. I wouldn't go to that stadium as that type of behavior just breeds further bad behavior.