Other mistake: Jack Twist's Thanksgiving dinner has a TV clip from a 1977 American Football game which cuts to Ennis Del Mar's Thanksgiving dinner which has an ice skating competition from 1980 playing on the TV, but then later the charity dinner where Jack Twist meets his soon-to-be lover has a banner saying 1978, two years before the previous Thanksgiving scene with Ennis Del Mar.
Other mistake: Research in the end credits is misspelled "Reasearch."
Other mistake: During the final showdown with El Guapo, three horsemen ride towards some fake Amigos and fall into a concealed ditch, throwing up their arms and falling off their horses. Unfortunately, they throw up their arms just before the horses even start to fall.
Other mistake: Early in the film Wayne and others have two steers tied, lying on their sides for branding when they are approached by Mexicans. Following a dispute Wayne kills one of them,a grave is dug and a brief service is held. Following this (which must have taken at least a half-hour) the same cows are still tied up; it is doubtful that a competent cowboy would have allowed them to be tied in that position for that long.
Other mistake: In one scene a station wagon pulls up with a 300 to 400 pound dead deer draped over the hood. Later, as the shot changes, one of the hunters can be seen in the background easily carrying the obviously fake deer.
Other mistake: When Jill tries to leave Sweetwater in the morning after Cheyenne's visit, she runs into Harmonica. He has a very nasty, coarsely stitched injury in his cheek that is not accounted for, and for which there was no time to be received, stitched, and the stitches removed again. (Special Edition DVD has a deleted scene in which Harmonica is beaten up, which explains the injury, but it is a continuity mistake within the regular movie.) (01:12:25)
Other mistake: When Bud is hit by the mechanical bull, he jumps up shouting "You broke my godd**n arm.", and this is a point thought the next 45 minutes or so. The cast he is seen wearing however is only given for a broken thumb, not a broken arm, which is where he was hit.
Other mistake: Jack takes the moonshine to Floyd Banner and sells 200 gallons @ $5 a gallon, ie. $1,000. When he gives the money to Forrest he tells him it's $2,000 minus his commission.
Other mistake: In the scene showing Fletcher hanging over the wreckage of an anti-aircraft gun after he was speared, the camera flies up above the gun looking directly down the barrel. The plug welded into the barrel to deactivate the gun under Australian gun legislation can be seen.
Other mistake: When Gregory Peck was being zoomed in on there are several fresh horse tracks.
Other mistake: During the first round of the duels we see a part of the participants list and "Scars" is missing. He should appear between "Spotted Horse" and "Sparks" according to their order of entering the competition.
Other mistake: As the tarantula approaches the first small desert town (when Lovelace orders Grant to surrender the government to him), look at the townsfolk. Not one of them pays any attention to the noisy, giant metal spider as it lumbers towards the town. In fact, none of them react at all until the first building explodes. I guess giant spider robots were a common sight in the middle of the 19th century West.
Other mistake: When Josey confronts the Comancheros, the Chief notes that they are facing the sun. You can see that the sun is on the back of all the characters who are looking at Josey...meaning Josey is the only one looking into the sun.
Other mistake: In the bedroom scene before Dan Evans leaves his family, there are two petroleum lamps attached to the wall and lit up although there is still daylight. Given their financial distress, they would have never done anything like this. Moreover, the light is not flickering because the film crew used light bulbs.
Other mistake: At the end of Goin' Courtin', Daniel says "fighting and trapping" in the wrong order. You can just hear him if you listen very carefully but it is really obvious if you watch his mouth. (00:36:55)
Other mistake: When Jimmy Stewart talks to George Kennedy about the taking of his son as prisoner. Right after they look at the map. Look over the shoulder of Kennedy in next few frames. You can see a white vehicle move across the horizon under the mountains. Looks like a white van or truck. With a HD TV, you can even see the dust trail as the vehicle moves left across screen.
Other mistake: In the opening scene, Mitch receives his birthday phone call from his parents. As he gets out of bed, the pillow case has perfectly ironed fold marks even though he has just slept the night in the bed.
Other mistake: Johnny Brown is serenading Molly in the meadow as she sits up on the branch of a tree. In shots where we are looking down on Johnny (from over Molly's shoulder), the shadow of the canopy that protects the actors from the sun can be seen as a perfectly straight line on the ground, behind Johnny. The shaded/unshaded areas move as the canopy shifts in the breeze.
Other mistake: The camera shows Jesse's "Prison Train" as it comes down the main line and whistles. As the train approaches the camera the driver opens the cylinder cocks and you see the steam shooting out from the front of the locomotive, at ground level. The steam cocks are never opened on a steam locomotive in motion unless the boiler is too full. They are actually there to let condensate water drip out the cylinders while the locomotive is standing idle, and to help the cylinders warm up by blowing warm steam through them. The action shown is equivalent to driving a car on the highway with loose sparkplugs.
Other mistake: In the shot where the men are playing a game of baseball, if you look carefully in the background you will see that cars are driving down the highway. Considering that this movie was supposed to take place in the 1800's...