Cash gains a beard when he walks into the cantina.
During the car chase scene which follows the failed bank robbery, there is a brief glimpse of a "flipped" shot, in which it appears as though Sgt. Coker is driving the getaway car from the right hand side, while the left front seat (the driver's seat in left-hand drive cars, naturally) is empty.
All of the military identifications expire December 31st of the year. Military IDs expire on the anniversary of the member's entry into active service or re-enlistment. It would vary for each individual.
When Sheriff Benteen realized that Major Hackett lied to him about working for the DEA, he ordered a deputy to get the "Federal Drug Administration" on the phone.
The two bad guys that get stuck in the sand are driving a 1986 Dodge Lancer ES. An 86 Dodge would not have had a bumper jack like the one used to free the car.
El Pasoans don't speak with a Texan accent. They speak with the standard American accent.
When Scarza is hopping on his right foot after being gruesomely shot in the left by Jack, the lower part of his left leg can briefly be seen to be a prosthetic, as the actor hides his real lower leg behind him by bending it at the knee.
A microphone is visible in bar scene at the beginning (a few minutes from the start).
A microphone is visible when Hackett (Michael Ironside) enters the bank and asks a lady at the counter where to meet the director of the bank.