I think all of your objections are really a bit nitpicky. For a horror/drama, this one was no worse than many others, and in many ways, was quite superior. I can’t remember enough to comment too much about it, but the list above is not at all fair in trying to dissect this kind of movie. Cops, being people like the rest of us, do dumb things, doctors DO have free time, there are enough poisons/nerve agents out there with which most people are so unfamiliar that it isn’t too taxing to believe such stuff. If somebody had told me what a buzz I would get when I went into my surgery, I wouldn’t have believed them, so I can venture that many doctors can tell us some things about drugs that would make the plot within, if just barely, the suspended disbelief range. btw, it is really unfair to attack the waking at the same time thing. If you want to have that kind of reality in it, you’d need about a 5 hour movie. The alleged stiff on the floor difficulty would not even enter into discussion. If you were locked in a room with a body on the floor and a pool of blood by a guy’s head, and a bad smell in the room, and I can’t remember the rest, nobody would look at him after their initial discovery. What else would there be to look for? Green? Flies? Rigor mortis?
No, you are being hypercritical, and doing an injustice to a good horror movie.
Saw II, now, that bit big time!! Haven’t seen the other 28 Saws.