wonder what this guy was thinking

This is were passive racism comes into play. Did he really mean to call the black man a 'macaca' or did he make a honest mistake?
I am leaning toward passive racism personally. I don't think you accidentally call someone an insult like that without knowing what it means.
The funny thing is that as one who has been discriminated against due to race (ethnically speaking I'm malay-chinese), I would urge people to make a distinction between passive racism, or making a distinction between races, and active racism.

Passively, if I were to adapt Kant's fundamental table of cognitive function, I could argue that we make a distinction between that which is of us, and that which is not of us. The old familiar Harvard study suggested that more likely than not, race is one of the things we judge by. Well, not so much race, but the appearance of race. It implies that a fear of other races is simply like a fear of the other, which is to say it's endogenous.

However, since I didn't the article, I'm not sure (and likely this isn't the case) that the comment was a simple slip of the tongue from a habit not derived from racism per se. What is racism? Or rather, what do we find objectionable about it? I thought that it was the cognitive belief that differences between the races meant that one could claim superiority of one race over other races. What's even more objectionable is the actions that this would justify.

The part I'm interested in (perhaps this should go into a discussion on racism) is from a more generalised mechanism- rationalism dictates that we need to justify our beliefs and feelings. I'd suggest that this mediates the treatment of the premises of these discriminatory beliefs- racism, specisism, homophobia etc. If people as a whole could learn make the distinction between something we feel, something we think and the moral implications whatever they are, then perhaps discriminatory behaviors and arguments mightn't be quite so prevalent.
Interesting thoughts... I hadn't thought of it from that angle...
start a thread about it.