It was a slip he made. Subconsciously bringing an analogy up that revealed his deeper beliefs. To him the Nuremburg trials were an injustice. For most people, we would have just executed the SS but the World had to see it. The antiSemites wanted it hidden - what the Germans did. And like most ignorant lefties, for Clapton there is no history unless it fits his narrative.
Having said that, he is the greatest guitar player of all time. I listen to his work almost every day.
Sorry. Buckethead is the greatest guitar player of all time.