Reminds me of a typical exchange we might see between a group of cosseted upper class girls, and street hardened lower class boys. Though I am not saying it is the same.
But how would any bunch of girls subjected to an abusive confrontation on a train relate to it afterwards, if they never saw the class disparity that exists, until then, and in this case, maybe not even after then? In this case the boys picked on the language disparity, but in any situation, in any country, accents alone are enough to trigger animosity.
Doesn't excuse them, they were a few idiots, it is a shame there were not more on the train from the same background who might have been more inclined to defend you.