Boy oh, boy, whatever are we to do with people who refuse to accept that others have different customs than themselves.
So, look here muchacho, you will need to catch up mosh gosh, capice? That's as my old First Sergeant Comacho would say ~ and he could say a lot of stuff in many languages any time he wished.
As others have pointed out, if it was a religious or cultural thing, how come he only addressed Cain that way. Struck me that perry was attempting to diminish Cain by trying to talk “black” to him.
In less enlightened time, that was exactly what the word “boy” was used to do.