That seems more like nitpicking over definitions than anything relevant to this matter.
Your quote and several other parts of the story focus on the number being "made up" and yet the same person quoted by you also says:
> The problem, according to Bauer, who has debunked the number repeatedly in his writings over the decades, is not that non-Jews were not victims; they were. It is that Wiesenthal’s arbitrarily chosen tally of non-Jewish victims diminishes the centrality to the Nazi ideology of systematically wiping any trace of the Jewish people from the planet.
> In fact, he said, the term “genocide” could accurately be applied to the 2 million to 3 million Poles murdered and millions more enslaved by the Nazis. But the mass murder of the Poles, Roma and others should not come under the rubric “Holocaust,”
So that's up to 3 million Poles, up to half a million Roma, which only requires "others" to make up 1.5 million for the "made up" number to be exactly correct. A quick Google suggests about a quarter of a million disabled people, 20 thousand gay men. So in reality this seems a surprisingly accurate "lie".
What he appears to be mostly concerned about is that the term "Holocaust" be a specific term for the Nazi genocide of Jews, and other terms be used for their genocide of other groups.
If anything, his dramatic quote about telling Simon Wiesenthal he was spreading a lie is a better example of someone using drama to advance their opinion