Tessa, to answer your follow up question, I do not believe it was murder (as in intentional), I believe it was gross negligence on the part of the doctor. My understanding is that the drug he was given should not have been given in a home setting. Also, the fact that the doctor stepped away was a problem because (from what I read) anyone under the influence of that drug should have been closely monitored.
It's quite sad. We truly lost a legend. Regardless of his personal issues, he was a musical genius and loved by people around the world.