You pointed out he was an African immigrant, while mentioning it was superfluous to the statement. You could have easily said "some guy"...
Just sayin'

I said it to emphasise that he might not have been use to the customs of my country. It really doesn't matter though, the point is that this guy tried to punch me for something that was really petty, which is what this thread is about (weird random stuff happening).
And plus, there's nothing wrong with being called an immigrant. My parents are still called that, where people ask them "you're not from around here are you?" and they reply happily with "Yeah, we immigrated here from etc. etc.", ....and they've been in Australia for well over 25 years!
Hope that clears it up

Note: My parents also did pretty weird stuff when they first arrived here in Australia. They would do stuff like stopping in the middle of the road when the pedestrian lights told them to stop walking. So when I say "immigrant", it's solely to point out how cultural differences can cause someone to do stuff considered "out of the ordinary" that can be a source of randomness/amusemant.