Yeah I actually know what you are talking about- not that I had the exact situation with your uncle and his past- but with my dad's mother when she died.
In all honesty she just wasn't a nice person and though it seems bad to talk about someone who has passed like that it was tough to be around her when I was growing up and later as young adult I had a lot of problems with her when my father died. She didn't make things easier for my family and especially my mother dealing with his death, the circumstances about it and the funeral. It's something that always bothered me mainly with how it affected my mother and what she had to go through. I don't hold it against her now as time has passed and she is no longer here but I will never forget what it put my mother through.
When she died, as cold hearted as it sounds, I didn't mourn in the way that I was losing someone close to me, close to my family by blood but not in feeling to me. I was chosen as a pall-bearer and I remember thinking I wish they would have chosen someone else who felt more for her for that role. I was sad to see how it affected members of my family but it definitely didn't affect me the same way. Not to say I was happy she was gone at all but for good or bad it did not affect me very much.