Factual error: The evil man request 10,000 pieces of gold for ransom. Each gold piece looks to be about 10 ounces, and 10,000 of those would make the entire thing of gold weigh about or over 3 tons and 2 guys are carrying it around in a little chest throughout the movie.

Continuity: When Jackie goes into the tent (at the coal mine) to talk to the Princess, it is broad day-light. When he comes out (three minutes later) it is pitch black out side.

Continuity: In the scene in the desert when Roy is buried alive, Jackie walks up and casts a shadow over his face.  In the next camera shot, the shadow is facing a different direction. It continually changes throughout this scene.

Revealing: This mistake occurs in the beginning of the film where the bandits rob the train. When Jackie is standing on the coal (or was it wood?) car you can see the train is passing a modern sign (you can see it on the right).

Continuity: Jackie Chan fights the Indians in the stream. His clothes are soaked. But as soon as he is on the land to fight the others, his clothes are dry.

Visible crew/equipment: When they are breaking out of the jail cell, when he opens the door, there is a person that holds the door open.

Continuity: At the end of the hanging scene when the horses and wagon charge the gallows, the wagon hits the structure, the sheriff falls, you can see the horse break free from the wagon, leaving it under the fallen gallows. The next scene the horses are back attached to the wagon again.