Trying to remember the title of a particularly shitty sex comedy which sort of used this trope; three different people were trying a kill a rich old uncle for his inheritance, but all their methods were cancelling each other out (one was trying to poison him with blood thinners, one with blood thickeners, and one was trying to scare him to death - the adrenaline boosts were helping him ride out the strokes from his blood going haywire). And it eventually transpired that he'd been accidentally killed by a fourth person who wasn't trying to kill him at all, but his OCD cleaning spree poisoned him with bleach. And then the guy's will turned out to be in a jar of mayonnaise, or something.
-Edit- Found it - "The Naked Detective". Rat poison (thinner), vitamin K (coagulant), and failed attempts at shooting (adrenaline). Well, I did say shitty.
Edited by 94.0.40.109
In future, I recommend You Know That Show For this sort of thing.
Edit: This was supposed to be a reply to the other discussion thread, but I messed up.
Edited by birdsinthewindow