The sad thing is, I'd lay money on the Royal Family not seeing themselves as racist. You and I both know the type.
That said, they didn't use the word racist in the Oprah interview, but they knew they were describing it. So did the world. You don't have to use the word to describe it. Back then, I was pissed that he didn't name who asked about the baby's colour. Maybe I'm just too much of a loud mouth, but, if something bothers me enough to talk about, it bothers me enough to name names.
If he loves his father and brother so much, he should absolutely call them out, as far as I'm concerned. All he's served to do is exactly what you said, destry his credibility and give the reacists in the family and easy out, thereby setting us back.