i think on some level it's hard for parents to outright HATE the person they raised from birth. they can strongly dislike, disown, and get away from them if they turn out evil but on some level that parental love will always be there. it can be outweighed and hate can exist at the same time, but SOME connection to the kid they once were isn't going to go away very easily. so yeah, they might love them, and never excuse their actions or approve or try to justify anything (including the deserved hatred that person is getting)