Even assuming everything they say about the Nazis is true, the only thing unique about them is how they made an inefficient but more "civilized" method of doing what most empires in history did at some point.

So what makes them special is they didn't just shoot you in your bed and burn your house down, they put you on a train to a camp instead.

And given the amount of "Holocaust survivors" who keep talking, clearly they were pretty lax at killing people at those camps.