Sounds like sour grapes, not discrimination...
I moved coast to coast to work for a SV technology company (fully paid), did NOT graduate from a fancy college (or any for that matter), have my nights and weekends free, and see the struggle daily that is the fight to find qualified talent... Truth is that tech companies are having an extremely hard time filling seats, and they frankly can't afford to discriminate on anything other than lack of skill necessary or extreme culture mismatch.
The only thing I agree with in this article is that yes, 3 times is a pattern... a pattern that they don't want to hire him. Maybe he should figure out why that is before blindly blaming it on race.