Well a Canadian man in the USA making fun of a Pakistani man in the USA could easily be racism, even if it is subconscious. White men are the socially dominant group in the USA, and it is people of color who have told me about this issue with masculinity. A man from Pakistan and a man from Canada get treated very differently in our society.

But the behavior is also just plainly sexist. The implication of racism is just extra bad.

I'm not American, but he just seems like he is rude and unpleasant to everyone.

Dinesh gets it the most because he has the most interactions. Of course it could just be racism, veiled as general cuntishness.