I have read his well published autobiography. He had no diplomatic immunity. The Nazi regime did not recognise his fatherhood.
The unlucky Blacks were those born to Senegalise soldiers who occupied the Rhineland with the French army. Those were handed out to the Nazis by their local authorities.
I watched his documentary on how he tried to be accepted and was rejected by the nazis. Didn't know he migrated out and became a journalist. He was Lucky but I believe the reason why Nazis didn't kill him is because his dad was diplomat and he had diplomatic immunity
You're right other Black Germans were mistreated and chemically castrated.