Christophersen was stationed around Auschwitz throughout 1944. In his original work Auschwitz: A Personal Account, however, Christophersen clearly states several things which are blatantly false, or which show just how unreliable his testimony is.
1) In his book, Christophersen heard word from his mother and his maid that corpses were being burnt in the crematorium, and of a (probable) fire that constantly reflected off of the sky. Christophersen supposedly went in search for an answer (p.19):
So I went in the direction of Bielitz and there found a mining camp in which some inmates also worked. I travelled around the entire camp and examined all fire grates and all smoke stacks, but found nothing. I asked my colleagues; the answer...a shrug of the shoulder and "don't pay any attention to these rumors." Actually, there was a crematorium in Auschwitz, I was told, for there were 20,000 people there and any city of that size has a crematorium. Of course people died here as they did elsewhere, but not only inmaes at the camp. The wife of one of our supervisors had also died here. As far as I was concerned, tha was enough of an answer.
From the quote, it is clear that Christophersen was not personally familiar with Krema I (main camp), but rather had to rely on the statements of others. Also, as Christophersen limits his answer to a single crematorium, it is obvious that he was unaware of the four Birkenau crematoria. As these were theforemost sites of the gas chambers in Birkenau (and he doesn't even know they existed), just how credible are his conclusions that there were no gas chambers? Christophersen obviously did not go far enough in his search.
2) Christophersen goes on about the burning of corpses (p.20):
Olga loved to constantly chatter and her continual gossiping, rumouring and wondering as to wheher or not corpses were being burned (whilst I knew for sure there was no such happening) finally got on my nerves. This, plus her almost slavish servitude, brought us to a parting of the ways. She was given a new job, one I did not begrudge her.
While Christophersen states to have "knew for sure" that corpses were not being burned, the available aerial photography betrays his falsehood. Indeed, we just discussed such photographs on this forum a month ago.
Revisionist heavyweight Carlo Mattogno also has stood by open-air cremations in 1944, as well as the fact that the Birkenau crematoria do (occasionally) smoke.
3) Christophersen flirts with crematoria-denial, stating (p.22)
After the war I saw a TV film about Auschwitz that showed a building with huge smoke stacks. I am very sorry, but when I left the camp at Auschwitz in December 1944, I did not see this building. I cannot imagine that these smoke stacks were built in the cold winter of 1944/45, but I suspect that these structures were erected after the war. It also seems implausible that, if they should have existed, the SS did not destroy them.
As no images of the "smoke stacks" are presented, it is hard to say which building(s) Christophersen is referring to. Anyway, it is well recognized by modern "revisionists" that the Nazi camp had five crematoria, none of which were forged or built into existence. This quote illusrates Christophersen's willingness to easily discard that which does not agree with his own (limited) view of the camp, despite a preponderance of evidence.
4) Furthermore, according to Christophersen, no one was shot at Auschwitz (p.22-23):
During the past few days I have heard a report on the radio according to which 4 million people are supposed to have been shot at Auschwitz. It is an absolute certainty that no people were shot at Auschwitz, because this we would have heard.
That this fact is disproven by camp records (especially those which state 'auf der Flucht erschossen') and is hardly questioned by most revisionists is noteworthy.
These are not "lies" (Heydrich choose to call them) put into Christophersen's mouth, as they are his documented statements. That he may have subsequently changed them (to allow some shootings, to move them outside camp, to allow some smoke, some open-air cremations of corpses, etc...) shows either:
1) the unreliability of his account
2) the deterioration or improvement of his memory, or
3) the influence that post-war information had on his own 'memory' and perception of the camp.
Either way you take it, Christophersen's account can NOT be used as a reliable indicator regarding the exterminations (or lack thereof), for he was NOT in a position to know.