I have no idea who this guy was, or anything about him but..
Where I am from you don't speak poorly of the dead.
I've always found this notion to be completely ridiculous, if someone was a jerk, their dying doesn't change that fact. Does this saintly notion apply to Hitler, Stalin and Mao? They are all dead. Hitler, Stalin and Mao where evil monsters... see I just did it. (speak poorly of the dead that is.) This idea implies that it's alright to say anything you want about them when they're alive, but as soon as they die, every fallacy and sin they had must be forgotten.
If someone asks, I'll speak my mind, I don't care whether the person I speak of is dead or alive. From what I've just learned about this Dunn guy -that he starred in a show call jacka--, and drove drunk- I don't think very highly of his character, his being dead does nothing to change his character, his character and integrity are defined by what he did while living. He doesn't get a clean slate just because he is dead. Why should he, maybe his friends and family can learn from his mistakes and flaws now, and perhaps his death will save them from doing something equally stupid.
Of course all his relatives and friends will sugar-coat things at his memorial/funeral, they have to, it helps them to cope, focusing on the good, and overlooking the bad for a little while, and that's fine as long as it's only for a little while, we all do it when someone close dies. But it doesn't mean the rest of us have to put blinders on just because they are dead.
We all have fallacies, foibles and problems in our life and our character, whitewashing all that away when we die is a disservice to us and those close to us. I want to be remembered for all that I am, and all that I did, not just the good parts. I also want to be forgiven for all those things, but forgiveness does not equal forgetting. I want my failings an mistakes to be remembered too, so that perhaps others may learn from them.
*BTW the novel
Speaker for the Dead by Orson Scott Card is a great philosophical read that deals with very subject.*