Let's see if I understand this correctly. I'll put myself into the camp and decide whether to evacuate with the SS or remain behind to come under Soviet juristiction. I could see that the SS was gassing and killing all Jews such as myself in homicidal gas chambers. I couldn't be sure if the Soviets would harm me or not. What choice would a prudent man make? Certain death by the SS after their use of me for labor was over or the possibility that the Soviets might harm me.
If there were actual homicidal gas chambers as told by the exterminationists the choice to remain behind is obiviously the prudent choice. The fact that many chose to be evacuated with the SS belies the existence of homicidal gas chambers in Auschwitz. Oh, I forgot; the people that chose to go with the SS didn't realize that there were homicidal gas chambers, didn't see the smoke and smell the burnt flesh. It was a big secret.
You couldn't be sure if the Soviets would harm you?
If you were Russian, German, Hungarian, or Polish your death sentence was a given.
How is it you could see that the SS was gassing and killing all jews such as yourself?
If that were the case, why did they not kill Otto Frank, Primo Levi, or any of the other six thousand who chose to stay?
If you were a typical jew in the camp, you "heard" that jews were being gassed. Or perhaps you managed to get hold of one of the propaganda pamphlets that were air-dropped and littered the countryside.
These too stated that jews were being gassed.
If you were part of the selection process, as described by Primo Levi, all you saw was that those who were determiined to be unfit for labor were taken "somewhere". You did not see them taken to a "gas chamber".
However, if you were a typical jew, you read the War Refugee Board Report after the war, and surmised that the "rumors" you heard during the war were true.
How does seeing smoke, and smelling burning flesh prove the existance of a homicidal gas chamber?