I think the gay angle is more important here than the black / white one. Perhaps a pick-up gone wrong?
More likely just an a-hole with a very large chip on his shoulder.
From the article:
Michael McBain had just returned home to his Capitol Hill condo with his wife when two steps inside, a complete stranger beat him unconscious.McBain was punched in the head and kicked in the face. "There was a big guy standing there, sort of blocking the door. And I guess I must have brushed past him," he said.