Something British?

I have seen something really British for me.

When I was walking near the Kentish town station, I find a young lady and black huge man arguing something. For me that black huge shouting man looked scary however the young lady did not look scared at all and shouted back to him. If I got shouted at especially in Japan, definitely I will be scared because people who shout seem lost their mind and they might do something violent. When I saw this young lady and huge man arguing, I realized that people are not supposed to do violence ever here even if they shout each other. Is is correct?