The author is stupid enough to use the word 'debunker" in a extra stupid way.

Nice catch, Uncle Bill. I don't know if the author ever apologized, but check out the "To The Editor" section of the November Smithsonian-- another reader brings up the same point you just did:

I find it ironic that...author David Roberts refers to Eric Robert Rudolph as, among other things, a "debunker of the Holocaust." This in an article about word usage. Webster's defines "bunk" as "something pretentious and empty or plausible but erroneous, as a speech, an opinion or doctrine" and "to debunk, to divest of 'bunk.'" Those who would deny the historical fact of the Holocaust are more accurately described as "Holocaust deniers." Facts may be denied by the ignorant or bigoted, but one cannot "debunk" a fact. Norman Fried Oceanside, CA

I find the name "Holocaust deniers" entirely too polite for these poor excuses for human beings, but.