Interesting to read others' experiences in this area.
I'll start with my dad--when he asked me about 3 years ago what I was upset with, I gave him a long list of specific things (abusive things) he had said and done throughout my high school years, early adult years, and even in later adult years, including trying to choke me when I was 23. His answer: "None of that ever happened. You imagined it all." That's verbatim. He said I 'imagined it all.' Never mind that you'd have to be mentally unstable to the point of needing commitment to imagine such things, and the evidence of my professional job and good reputation and ability to raise my family and be respected by those who knows me suggests no such thing is going on.
From there, one sibling acknowledges being fully aware that I was not raised by the same parents she was. However, as she was 7 when I left home she would remember little of it--perhaps she's blacked out events, too? Some things, she would never have known happened at all. And in her mind, the answer is, "I know they treated you totally differently, but can't we all just move past this and get along?"
Another sister fully acknowledges the lousy things my parents did, but still tries to be the good daughter and please them. Because they're all mad at me, now, I suspect it's in her best interests to stay on their good side so they continue lambasting me instead of turning on her and telling her in no uncertain terms she should have controlled her temper. I'm sure at this point, she'd never admit to me the things she previously admitted.