Let us not forget one thing. Junkies don't shoot up and THEN shoot self.
I am willing to stake my reputation on this fact. Heroin junkies may want to kill themselves when they are in withdrawls or maybe even when they are coming down off the drug several hours later but for an addict to shoot up and then blow their head off? It goes against everything the drug is. Would love to see a similar case to cobains.
I post this just in case cobain could remain conscious after a dose like that...which he could not.