My grandad, have I missed something

[IShouldBeBothered]

I'll keep this short because I don't really know anything. I'm posting because I don't know quite what to make of it but the bottom line is I don't really believe it.
So my dad recently told me my mum was sexually abused by my grandad.
He's been dead 30 years and I have nothing but good memories, particularly all the alone time I spent with him and my sister.
My mum has never mentioned it, if it did happen then would she not have kept us away from him, particularly alone.
Something to add is my dad was seriously ill over the last couple of years and in a medically induced coma for a long time.
Could he be imagining or "mis remembering ", if that's a thing.
I haven't and won't ask my mum, but I wondered if anyone has any experience of possible false memory.
Just trying to make sense. (I remember my grandad very well from an early age so no possibility I've been harmed)

[Idoknowwhatyoumean]

If you google false memories after medically induced coma you will see quiet a few people do experience this so it is possible that your Dad is thinking about a false memory, or confusing who was abused/abuser, or even mis remembering after hearing staff talk in the room with him like...

My wife was in a medically induced coma for 2 weeks. When she woke she had very wrong memories. They were all based on conversations people had while in the room with her. For example, she thought they flew her to Washington, DC for treatment. While she was in a coma, my father-in-law mentioned how he had just flown back into town from DC on a work trip. Somehow, she overheard this while out and her brain interpreted it to mean SHE flew to DC. Even after we explained to her where she was

The drugs they give patients does do funny things and can cause hallucinations. It’s also a very confusing time after the meds are reduced and patients wake. DH had disturbing flashbacks for months that had him waking, screaming in the night.
You know your mum best but I can’t imagine I would let my child be alone with someone who had abused me in childhood. If you really don’t think you could raise it with her, and either confirm what your dad has told you or give her the chance to correct your dad, then it is better to be forgotten.

www.thecut.com/2016/07/the-man-who-woke-up-from-a-coma-with-memories-of-another-persons-life.html

www.oversixty.com.au/health/mind/man-wakes-up-from-coma-with-different-memories

[IShouldBeBothered]

Thank you for your reply, that makes a lot of sense x