Perhaps you found yourself wondering after reading the last post, "Why did the mother go back and look again for the record?" It seems like a reasonable thing to do. Reasonable and narcissist aren't usually the words we use in the same sentence to describe something about narcissists.
I've had the same question. Of course, I don't have a definitive answer because my mother never talked about this event with me, but I do have a very good explanation. Knowing my mother as I do I realize now that even though I was infuriating her with my insistence on my innocence, that very insistence was disconcerting to her. She had ramped up the rage to terrifying levels and still wasn't able to get me to say what she wanted me to say. My general overall nature as a child was compliant. Fear tactics were consistently quite effective on me. So, I am convinced that my willingness to stick to my guns even as she kept ramping up the rage finally to the point of openly wishing she could kill me...and seeing me crumble into sadness yet still insist on my innocence; it broke through her narcissistic defenses and forced her to reconsider the possibility that I was telling the truth. I am convinced this is the reason she did what a reasonable person would do...go back and look.
Another thing. My mother was around 30 years of age. She was not the hardened narcissist she became later, though she was well on her way. There was still some modicum of hope for her back then. She could be cruel to her children, but she could have been much more cruel than she was. Something held her back. She still had some idea of what reality was. Back then she was still able to see herself as others might see her which kept her from overt manifestations of abuse, both physical and psychological. The person she was most interested in seeing her as being June Cleaver was my father. (As disengaged and lousy as he was as a father, I have been grateful for his presence in the family. Just by being there he provided some protection for his children. Had they divorced I know my life would have been much, much worse.) Anything she did to me or my sister could not leave outward marks. She did physically abuse us, but she was careful to do so in a way that wouldn't be obvious. Mostly, the physical abuse was accompanied by overwhelming psychological abuse. Just enough of the physical to convince us she was capable of doing worse. At that time, her children were the only ones who saw the seething violence just under the surface. But because she could hide it from my dad and others she could pretend it didn't exist. To this day, only children and two elderly family members have seen the violent rage of my mother. She consistently saves it for the helpless and voiceless. Cowardly bitch.