IDK about this one. Look to the One Drop Rule for explanation. For far too long has a single drop of black blood made a person Black, however once they achieve a level of accomplishment, that historical measure is thrown out and every other ethnicity is highlighted by folks. If he's walking down the street, he's your avg black guy.
He gives praise to his white mother and grandparents, yet in America and to the world, he is defined as a Black man. Nothing wrong with that.