There’s not much more I can say about his death than Arron Sorkin said here. That is, that if you’re addicted to heavy drugs like heroin, the odds are decent good that you will die. It’s part of the territory.
I have never had a drug or alcohol addiction, so I can’t relate to that problem specifically. Though I occasionally have a glass of wine (usually never finishing the glass), I’ve never been truly drunk in my life and I’ve never done drugs. One could argue that at various times in my life I was addicted to food, but I don’t think that’s the same thing.