I didn't hear what they said, but suddenly the asian guy grabbed the other by the shirt and started pushing him around, yelling and swearing loudly at him. An older couple further down told him to mind his language, and said if they wanted to fight they could get off the bus. Fair enough.
But then another older man started saying "Go back to Afghanistan" (despite the fact there was no reason to think he was from there) and making other similar comments. He repeated these comments at intervals throughout the journey.
Things calmed down, the first young guy settled at the front of the bus, and, after another altercation the asian guy got off.
Passengers indignant that driver wasn't doing anything, first guy indignantly assuring everyone he'd never seen him in his life before. As I got off, I felt indignant too. Not because of the fight, but because all old people are basically a bunch of racists.
But - wait a minute!
Have I not just done the same thing? I may not be racist - but if I label all old people as racist I'm just as bad. Just as prejudiced.