Corrected entry: When Carson Wells spots the money briefcase from the bridge, it is in the bright sunlight. In the next scene we see him returning to his hotel at night, so obviously at least five hours have passed. We know that Wells did not retrieve the money, since Moss retrieves it later. It seems very unlikely that Wells would have just left the money on the riverbank after discovering where it was.
Correction: Wells did not retrieve the money because he knew Chigurh was also looking for it and intended to use its location as a bargaining chip. Unfortunately for Wells, his plan did not work out.
Corrected entry: Chigurh calls Moss's mother-in-law from a pay phone. When he hangs up the phone we do not hear the coin mechanism cycle in the phone, even though the camera is very close to the phone.
Correction: If he used an operator, and a credit card, there would be no coins to drop.
Highly doubtful a hired professional hitman would use a credit card to make a phone call.
Corrected entry: Late in the movie, when Chigurh is involved in a car accident, the car running the light hits the passenger side. In such an impact, the driver would be propelled toward the passenger side. However, he gets out of the car and is injured on his left arm and the left side of his head hits the driver's window as if the car had hit the driver's side.
Correction: The initial impact would "push" Chigurh to the passenger side, but once the car stops, he would then be slammed into the driver's side door, causing the injuries seen.
Correction: Carson Wells did not retrieve the money because he planned to wait until very late in the night when there was no one around to get it.