You're a lofty little f***er. God, we're not all bumbling idiots, you know.
I don't believe it's cowardice that makes blatantly racist men say they have black friends. Racism in contemporary times is often more of a class issue than anything. It's the fact that minorities tend to be lower class. It's a matter of stereotyping.
For example, someone racist might say, "Those blacks are stinking up my street" referring to the overwhelming amount of black homeless people. Such a person might see that the homeless people are mostly black and therefore associate the poor, seemingly inferior state with the race. However, the same person might work in an office with a rich, educated black person and, though being immediately turned off by the fact that they're black because of the association this person has made with black people and squalid homelessness, realize soon that the black office worker isn't like them and is therefore, "one of the good ones".
Another example: someone might associate black people with being loud and obnoxious. If they dislike these qualities, they might assume that the whole black race is like this and, in turn, dislike all black people. However, if they meet a soft-spoken black person, "one of the good ones".