IMO, there's a time and place to share such details and after they've committed suicide, to speak so poorly about that person (whether true or not), is classless and tacky. I think that most people know that you shouldn't speak ill of the dead. I also find it strange that after so many years he clearly harbors so much animosity toward her. We all go through a bad relationship at one point in our lives but if it was 15+ years ago, we generally tend to move on and chalk it up to a learning experience.
Perhaps he should have chosen a woman closer to his age as opposed to a young pretty blonde bombshell (what a trophy for him!) who was very new to the world of fame.
Up until him, I have never read comments like his from anyone who had a bad relationship with an ex who has since passed. Most people have the good sense to be very general in their comments and be respectful, if nothing else, to that person's loved ones. If what Cain said was true (and not some media dog putting their spin on things), then I think he has no class.