The Choice discussion

It's awful to question any part of a holocaust memoir but I can't help but wonder about the way certain events were described and what we know of how Auschwitz operated. Two specific examples--Dr. Mengele appears to begin to rape the author but hears a phone ring, tells her to stay put, the author runs to escape and that's the end of that? (I.e., no punishment for running away?) Similarly, the author's sister is described as being shot at while she's foraging for food at a farm during a march, but they miss and she's able to casually rejoin the line? (Other memoirs would describe SS responding with collective punishment if they didn't know who ran or if someone actually got away.)