No, what your grandfather passes down is what people wanted to remember, shaded by their world view. Sometimes it holds things pretty good, but a lot of the time, when you go back and check the record books, it's been colored with nostalgia...or avoidance...Think of all those, "when I was a kid your age, I had to...." "Teenagers in my day didn't..." and so on.
My grandma grew up hearing how her uncle was killed defending a woman's virtue at a bar...we go back and checked the record, and he had been knifed by three husbands who were tired of him messing with their wives...
It ain't necessarily so. It might be, it might not. It's the documents that get left behind that tells stuff best...the account books, the diaries, the records at the general store, the court cases, all the bits and papers that anchor stuff to trust.
Oral history can and often does corroborate...but sometimes, it gets mythologized...
I haven't studied this particular set of stories myself, and I have no problem with it being one way or the other. But when you see what gets passed around and ends up on snopes, you know that sometimes things aren't exactly what they are talked about being.
I make no judgement to its right or wrong without doing some real study.