I don't mind how long it takes, if they are doing a thorough invistigation. I think they are going back years with these doctors, the CA governor is trying to stamp out these quacks who act as dealers.
We know what happened in the sence that he died because of propofol, he may not have died if Murrey had reacted properly and faster, and/or had the means to deal with a crisis.
The question is why? I am not going to be convinced he was so incompetent he did not know about the mixture of drugs and the potential hazzard of Propofol.
That leaves, him having no regard for Michael's life or safety, or murder.