I think he is not entirely wrong that there was a historian who exaggerated some numbers of non-Jewish victims, without thoroughly investigating the issue. However, it is my understanding that it is very well established that there were millions of non-Jewish victims, especially Slavic people, like this is on the holocaust memorial website and shows those numbers. It is clear that the Nazis also hated Slavic people and wanted to reduce their population and enslave the remainder, so this should really be considered as part of the genocide and not just "normal war", imo. I guess what this guy is saying is that it was more common to not send Holocaust victims from the USSR to the death camps, and instead many were murdered by the Einsatzgruppen in Eastern Europe. Then I guess some people might claim that these victims are not Holocaust victims per se, but instead just victims of the war. I guess autismdragon said this in a much more succinct way.