I know several people who take all of the same drugs regularly, just like him. I know because they all told me at some point shortly thereafter that they are taking the same things and were really freaked out by what happened to him.
I honestly believe that my mother truly died of an accidental overdose. Her death was ruled as heart failure, but without an autopsy or toxicology study, we'll never really know. I do know that she was cremated shortly after she died, which was her wish. Then, a few days later, when we were packing up her things, we found a whole grocery bag full of prescription medications, and all recently prescribed by the same doctor and from the same pharmacy. Among them were two different types of painkillers (Soma and something else), Valium, an MAOI-type anti-depressant, and an antibiotic because she had chronic bronchitis.
We thought about going after the doctor for negligence, but we had no way of proving that that was what caused her death, and she was not the least bit forthcoming with her medical records. We even had a doctor friend write a letter to the AMA asking them to require her to cough them up. She still never did. (Or they didn't even bother to make her - they protect their own.)
In any event, it's just one of those things that just happens. Doesn't matter how smart you are or how much you want to live. I had talked to my mother what turns out to be, we think, the night she died. She told me she felt awful, hadn't been sleeping, and just couldn't seem to get better from her current bout with bronchitis. I told her to please go to the doctor on Monday (this was Saturday), and that if she really felt bad the next day, to go to the ER (there weren't those walk-in clinics so much in 1992). She said she would.
When you feel like hell and you can't sleep, and then you haven't slept right for a while and so your mind is not your own, it's easy to forget when you took the last one or to just take another because the one you know you took an hour ago just ain't doing the job.
What makes me the saddest about both my Mom and Heath was that they were alone when they died. The fact that they were alone, really, is why they died. I was in Ohio and my Mom was in New York. I was worried about her, but not worried enough to call my brothers who lived in the same town as she and ask them to make sure she got to a doctor and was OK. Of course I've always regretted that. But hindsight is 20-20. I knew she was sick and felt awful, but I didn't know she had all those different drugs and was probably taking them all.