His opinion is backed up by factual data. He proclaimed that he is aware of being called a tribal and a bigot, not that he is one.
Many black people I have met have both positive and negative qualities. The negative ones really get up me arse, for lack of better words. When it comes to trying to make arrangements and getting them to perform their best and not leaving you to do their work for them, it can be neigh impossible. However, their familial culture tends to make up for this, but this is dependent on the understanding of the other person.
I'm mainly addressing the ones coming from Africa, not the ones bred in Western societies. However, it depends on which region of Africa, I find. I have also had the pleasure of meeting African Black people who come from the leftmost region of Africa who are very hard working, moral, timely and efficient - sometimes to an imposing degree. Many of which I have maintained close friendships and have had absolutely no issues making arrangements with.
So, he is entitled to his opinion because he has backed it up. He is only slightly biased in his experience, which he has no control over.
I'm not sure why you're making so big of an issue out of something so miniscule, unless there is an ulterior motive.