D-9035 is a black guy. "You wan' me to go down there, Doc?" See? He's a black guy cause he uses slang and calls the doctor 'Doc.' That makes him a black guy. And he's a big strong black guy. Who hates women. And doesn't appear to be particularly intelligent.
You should really look up the "black brute" stereotype, because it is exactly what you have described. Not only is this a stereotype and caricature, it's a racist stereotype and caricature. I have no doubt this was not your intention, and that most likely you wanted a shorthand of conveying to the reader that this is a big tough guy to make his mental break carry more weight, but his description and behavior display an immaturity in characterization.
This is problematic not just because of the negative stereotype it reinforces. Aside from the unpleasant subtext, there's no subtlety. You could have said, "Literally fucking Superman went down the stairs and got scared." It's a shorthand to play on media stereotypes we've all been exposed to rather than do the hard work of finding a character who can speak for himself.