Those who are dismissed as Holocaust deniers are often people not questioning that Jews experienced holocaust at the hands of the Nazis, but questioning the details of that experience.
That is not denial but it is called denial. Some of those questioning such historical details have been hounded, abused, professionally destroyed…. which is ironic really given that such behaviour is what was and is condemned in Nazism, Fascism and Zionism.
Surely if the facts stand they can survive all and every question?