Are chinese tourists always like this in Chiang Mai?

Forgive me for writing this while being somewhat angry. Until now I had always believed that comments made about the Chinese community visiting Thailand as tourists were unfortunate.

10 minutes ago I was coming back from the University on my motorcycle and I stopped at a traffic light. In front of me there was a tuk tuk with two Chinese men sitting as passengers.

One of them lit a cigarette and as it was the last one, he made a ball with the packet and threw it at the head of a university girl on a motorcycle who was next to me waiting at the same traffic light.

When he realized that he had indeed hit her, the Chinese man started to laugh while the girl looked resignedly at the ground.

And I'm not talking about young people. They were two men in their 40s. Is this a normal behaviour here? I am from Spain and they don't act like this in my country.