[Note: This post has been edited extensively as of 11:26 AM Eastern on 18 Apr to correct a slew of small errors, add an extended parenthetical, and revise some infelicitous language.]
Late to the party as is usual with us with these sorts of things, we've just viewed the 2008 Academy Award Best Picture winner, No Country For Old Men, courtesy of Netflix. As with all Coen brothers' movies there's much here that's engaging. But unlike other Coen brothers' movies this one contained two colossal logical blunders (among a number of minor ones) which all but totally short-circuited our enjoyment; blunders colossal because the progress of the plot depended and turned on each.
Colossal Logical Blunder No. 1:
Moss returns to the scene of the slaughter of the Mexican drug runners upon which he had earlier stumbled after he's already returned home safely and undetected with the satchel containing the drug money he found some fair distance away from the scene. The movie has Moss returning to the scene of the slaughter to bring a jug of water to the one Mexican drug runner who was left only half-dead after the slaughter and who was in need of water when Moss left him, but for whose plight Moss had shown a callous disregard when he first discovered him.
It would have been one thing to have Moss return to the scene of the slaughter not to bring a jug of water to the half-dead Mexican, but to make sure the half-dead Mexican was either already full-dead or, if not, to himself ensure that condition for the Mexican as he was the only one to have seen Moss's face even though he couldn't have seen Moss take the satchel containing the money.
But there's no hint that was Moss's intention in returning to the scene (he's bringing a jug of water for the guy, fer chrissake!), and in fact, hunter of animals that Moss is notwithstanding, Moss just ain't the kind of guy who could knock off a human being in cold blood; even some already half-dead Mexican drug-runner-type human being.
Had Moss not returned to the scene of the slaughter he would have been home free with the stolen money forever as there would have been no way for anyone to have known he was the one who took it. Of course, there then could have been no movie — or, rather, no movie as we have it — and so Moss has to return to the scene for whatever reason in order to be discovered and identified by those really bad people. As it's handled here, however, Moss's return to the scene is a wildly improbable deus ex machina employed not to save the day for the hero, but to save the movie for its creators.
(We understand the Coens' reasoning in having Moss decide to return to the scene with the jug of water. But the logical blunder aside, and contrary to their intent, Moss's return to the scene doesn't work to show the deep streak of humanity in him as much as it works to mark Moss as a moron with a death wish.)
Colossal Logical Blunder No. 2:
Moss very early on knows just how much money is in the stolen satchel ($2M). We know he knows not only because it would have strained credibility beyond the breaking point to believe Moss never counted it (what human being on Earth wouldn't have in the circumstance?), but because Moss tells us how much money is in the satchel (we overhear him telling his wife).
So, having counted the money, how come Moss missed discovering the electronic tracking gizmo stashed in one of the banded stack of bills near the top; a red-light-blinking electronic gizmo that's almost the thickness and size of a pack of regular-size cigarettes(!)?
Answer: Moss couldn't have missed discovering it. But the plot depends on him not discovering it so early on. That the moviemakers have him not discovering it almost immediately is nothing other than a colossal logical blunder on their part; a logical blunder made necessary because the plot doesn't work if the gizmo is discovered almost right away. And so another deus ex machina is employed; a negative one this time, so to speak.
The Coens should at least have contrived to have the gizmo stashed in a hidden compartment in the satchel itself even though real drug distributors as experienced and sharp as these movie drug distributors apparently are would never have made such a mistake. Or contrived to have the gizmo be as thin as a note or two of currency and absent any blinking red lights so that it actually could have been hidden reasonably successfully in a banded stack of bills. But, then, that would have been beyond the technology of the time (1980 or so), and therefore anachronistic.
We sympathize with the Coens being presented with this gizmo problem, but we nevertheless would have expected them to have solved it in a believable way.
Perhaps we shouldn't have been as enjoyment-robbing bothered as we were by these two logical blunders (they didn't seem to bother anyone else if they were noticed at all). But as Emperor Joseph II was wont to say, "There it is."