This is MY OPINION.
Was Joe a good dad? From all accounts NO. None the less, Michael was his SON. Michael had said in the unseen Bashir footage he had forgiven his father. Some people deal with grief in a different way, and obviously it wasn't good for Joe to talk about his record company or whatever a day or two after Michael died. But look in the past, Joe has always been a "business man" that's his nature. THEN, you have to think about this, he went to Michael's house to clear all things out, he had to have seen or at least heard about all of the medicine that were in Michael's house. This is before knowing everything we know now. You are angry because your child was trying to numb something and all the "what if's" run through your head (weather you want to believe it or not, we are just fans saying "what if", this is his FATHER, his FAMILY can you imagine their "what if's"?) AND THEN MONTHS LATER you find out that they died at the hands of another person? If this were my child, I would be out there on every news channel, radio station, magazine interview ANYTHING making sure that EVERYONE involved knew they were going down in some way or another. HIS CHILD WAS MURDERED.