When they are about to hang Billy Wade the sheriff and deputy show up. Clearly he is not wearing a gun. When the cut him loose and he escapes and rides off, during the chase when he comes around the rocks he is clearly wearing a gun and holster.
Several times it is said that the money shipment is coming from the Federal Reserve in San Francisco , the Federal Reserve was not created till 1913. They should have said the United States Mint or a National Bank in San Fransisco.
When the gang is on the hillside above the relay station near the end of the movie, there is an approximately 5-6 second shot of the gang looking down at the station, and in the last 2-3 seconds of the clip, the film is running backward. An outlaw on horseback appears at the bottom of the screen moving forward to join the gang, and when the film reverses he clearly backs up. Also, a branch is visible at the left of the screen bending downward in a gust of wind, and when the film reverses and the horse backs up, the branch moves in the opposite direction.
In the chase at the end of the movie, after the attack on the station, when Billy Wade is fleeing the relay station with the Wells Fargo wagon and Ike Garvey and his gang are chasing him, twice at the very beginning of the chase scene Billy Wade turns around with drawn gun and fires at his supposed pursuers, with the camera in front of him looking back down the trail behind him, but the camera clearly shows that there is nobody at all behind him that he can even see (much less shoot at). The view shows the entire trail behind him both times, all the way to a bend in the road, with no other horsemen on it. Meanwhile, the film intersperses the clips of Bill Wade frantically driving the wagon and shooting behind him with clips of the gang chasing him and shooting at him supposedly right in front of them.