In real life, he would not refer to himself as the HNIC.

Actually, he would have.

You have to understand that when blacks use the n-word toward each either, it's for satire or parody. That's why when that white assistant principal in the movie asked Ms. Levias, who was black, what did the acronym HNIC mean, she easily gives him the answer.

I think he probably did because his daughter created a Youtube for some of his videos and the name of the channel is batmanjchnic. Making reference to "batman" Joe Clark and "hnic" I don't think they'd give the channel that name unless its something he really said.

Those were the real Joe Clark's actual words.