Casual Person

Factual error: Just before Angel Eyes confronts the girl in her room about the whereabouts of Bill Carson, we see her walking in the hall outside her room, and lighting this hallway is a very modern day lightbulb.

Continuity mistake: A dirty Union cavalry officer hits himself to clean off the dust that made him appeared Confederate. His first two strikes barely shake the dust on his uniform, yet, after a cutaway and two off-screen strikes, his arm is almost completely free of dust. (01:16:50)

Fireball

Continuity mistake: When Blondie is saved by the mortar shell, and it shows the empty noose, it is completely different than the noose that Blondie had around his neck. The loop that the noose went through to hold it to the beam has changed.

Ian Hunt

Continuity mistake: When Blondie and Tuco are planting dynamite to blow up the bridge, they are standing in the water. During the following blast, they are hiding away next to the river and from then on, they are totally dry again.

Visible crew/equipment: When Angel Eyes sits down at the dinner table in his first scene, there is a small unlit lantern hanging on the wall near his head, and unexplainable light sources reflected on it.

Revealing mistake: When Tuco first enters Sad Hill Cemetery, you can see the dual tire track ruts left by the dump truck that brought in the sand to make the grave mounds.

Revealing mistake: After the explosion blows a hole in the wall and Tuco joins the procession of people flowing down the street, when the shot switches to face the characters you can see that the 'woman' in a blue dress in the wagon is actually a man. (Time is for the extended version of the film). (01:59:15)

xanderphillips

Revealing mistake: When Tuco is about to shoot Blondie in the desert, and the Army wagon is seen approaching, the driver can be seen sitting far back in the rear of the coach wearing a hat. (00:54:10)

Revealing mistake: When Tuco makes Blondie march through the desert, there is a shot at the very beginning and Blondie looks over his shoulder, feeling the strain of the desert. Then the camera focuses on Tuco and in this shot, you can see the tracks in front of his horse from a previous take.

Visible crew/equipment: When Angel Eyes has finished paying the legless man for information, the legless man hops into the saloon. Notice he has two shadows, revealing the presence of stage lighting.

Revealing mistake: When Blondie is to be hanged by Tuco, and saved by an extremely lucky hit by a Union mortar, you can see that the wall that will be hit by the grenade has been blown to pieces at least once before; the bricks have no mortar between them, and there is a large circular scorched area on the brick wall. (00:47:10)