Continuity: When Mortimer is trying to kill the man at the beginning of the film, he should be tracking his gun from right to left, not the other way around.
Continuity: When Mortimer picks up the wanted poster at the station, it has two handwritten zeros on it. When he slides it under the door, they are missing.
Continuity: When Mortimer unrolls the wanted poster before sliding under the door, it is obvious that the poster has a curled-up appearance. Once it's under the door inside the wanted man's room it is suddenly completely flat.
Continuity: When Colonel Mortimer first exits the train and speaks to the officer, alternate shots show his hand either on his hip or grasping his lapel.
Continuity: The orientation of the match that Mortimer lights on Wild's hump.
Anachronisms: During gunfight at the climax of the movie, automobiles can be seen driving on a highway in the background.
Anachronisms: Face on wanted poster of Indio is a high-contrast repro of a modern style photo.
Anachronisms: When Mortimer lowers the bible that he was reading in the train, in the background, you can see a fast moving vehicle driving down a dirt road.
Continuity: When The Man With No Name walks up to the poker game, the coins on the table change position between shots.
Audio/visual unsynchronized: When Monco confronts Red Cavanaugh, he shoots the three men who try to save Cavanaugh. After Monco shoots them, one of Cavanaugh's henchmen fires his pistol, but no sound can be heard.
Anachronisms: Playing cards of the Old West did not have modern numerals on each corner. The number cards were represented by the number of spades, hearts, clubs, or diamonds in the center, six of diamonds had six diamonds in the center. Also, the cards in the movie were modern machine cut plastic coated paper, period cards would have been larger, and of plain pressed paper or wax coated.
Revealing mistakes: When Indio is lying on the ground after being shot dead by Col. Mortimer, Indio's left hand (still holding the gold watch and chain) is turned palm down, with his left thumb pointing towards his body. In the next shot where Col. Mortimer retrieves the watch from Indio, Indio's left hand is now turned with his palm up and his left thumb is pointed away from his body.
Continuity: When Monco enters the saloon at White Rocks, his hat and poncho are dripping wet. In the next shot, they are totally dry.
Continuity: At the end of the movie when the Colonel shoots El Indio, El Indio's left hand that's holding the watch is by his left side. When the Colonel goes over and steps on his hand to get the watch, his arm is stretched out.
Continuity: In the end of the movie, just before the duel, we see El Indio reloading his gun. He uses all the cartridges in the lower left side of this ammo belt. However, when he goes out to the street, 4 cartridges appear again.
Anachronisms: Mortimer smokes a meerschaum pipe throughout the movie, which is historically accurate; however, the pipe stem is obviously Lucite, a late 20th century plastic. An 1860's pipe stem would be carved of ivory, antler, or bone.
Continuity: After he goes out of the jail, Indio faces an enemy in a duel. Alternate shots show the gun of the enemy either in front his right hand or behind his right hand.
Revealing mistakes: While breaking Indio out of jail, one of the bandits shoots a prison guard, who clearly reacts to the bullet before he is shot.
Continuity: At the end when Monco is loading bodies into the wagon and drives away, a tailgate is clearly visible hanging down on the back of the wagon. A minute later after he gets the saddlebags of cash, as he pulls away the tailgate is gone.
Continuity: When Mortimer is talking to the conductor of the train, his horse changes positions between shots.
Continuity: Near the film's conclusion as the two main characters exchange farewells in separate frames, Mortimer's close-ups and long shots show him against a setting sun. However, Monco's scenes, as the short shadows around him demonstrate, is in light that is much closer to noon.
Anachronisms: Tucumcari wasn't founded until 1901.
Continuity: After Monco's cigar is shot to a very short length by one of Indio's gang, subsequent shots have it both longer and then shorter again.