Continuity mistake: At the end the nasty man is out of bullets so the Bad girl throws him a bullet from her rifle. He puts the bullet in but fails to revolve the cylinder so of course he loses as you would have to thumb-cock and pull the trigger 3-4 times to get to the live ammo. Dumb, dead desperado.
Factual error: Approximately 2 hours and 10 minutes into the "restored" full-length video version, there's a birthday party for little Lisa Dickinson, and the Alamo defenders sing "Happy Birthday" to her. The Alamo battle happened in 1836. According to David Ewen's "All the Years of American Popular Music," the song "Happy Birthday to You" was composed and copyrighted by sisters Patty and Mildred J. Hill, first as "Good Morning to All," in 1893.
Revealing mistake: In the final scene as Doc tell Billy good-bye if you look up to the top right hand corner of the screen you can clearly see a jet trail in the blue sky. Certainly not possible in those days. (01:42:20)
Continuity mistake: In the barn dance scene Gideon is doing flips on the sawhorse. His shirt becomes untucked and then retucked between flips.
Continuity mistake: When Rick Nelson tells Angie Dickinson to throw the plant pot through the window to distract the gunmen who threaten John Wayne he seems to have had a hair cut between scenes as his sideburns are halved by the time he reaches the street and grow again later.
Revealing mistake: After Manco beats up Cavanaugh and places Cavanaugh's back up against the bar, while Manco faces him, three of Cavanaugh's henchmen appear at the entrance of the bar demanding that Cavanaugh be released. Manco turns around and kills all of them with his pistol, while Cavanaugh falls to the floor crawling toward his gun. Manco is walking toward the entrance of the saloon with his back to Cavanaugh. Manco draws his gun and kills Cavanaugh without looking at him. If you look closely at the tip end of the pistol, you can see that the only thing that Manco would have killed was the saloon floor. (00:17:00)
Continuity mistake: There is no way the cow (a Hereford I think) could have given birth to that calf (a Jersey or something like that). [The mom is a mixed-breed BEEF cow, the calf a purebred Jersey DAIRY calf. An amazing feat of animal husbandry.]
Continuity mistake: At the fair when Isabelle goes to give Suzanna the baby, she actually hands it to her in one shot, but in the next (a split second) Suzanne shows no sign as if the baby ever left Isabelle's hand. (01:38:24)
Revealing mistake: When McKay and Ramon are riding into Blanco Canyon to rescue Julie, you can see a diesel loading shovel with its bucket raised in the bottom of the frame of one of the scenic shots. Presumably the scene was shot in a quarry and they didn't get all the equipment out.
Factual error: When Bob Ford opens the box under the bed, on top is an issue of "The Jesse James Stories" weekly, which was published from 1901-1903 - fully twenty years after the events of this film. (00:36:10)
Visible crew/equipment: At Lees Ferry when the stagecoach is crossing the river, there is a shot from on top of the stagecoach. As the camera pans over to the river, a clear shadow of the camera and its film magazine are visible.
Continuity mistake: When Jack Twist is chopping wood, right before Joe Aguirre visits him on his horse, he sets up a piece of wood to chop. Jack talks to Joe and when the camera pans out to show him ready to chop again, the piece of wood is gone.
Plot hole: Towards the end of the film when Newman and the remaining stagecoach people are in the cabin at the top of the hill, Richard Boone's character sends one of his two henchman (the Anglo, not the Mexican) around to the back of the cabin to apparently surprise them from behind. Then Newman's character walks down the hill and Boone and the Mexican henchman are all killed in a shootout. Everyone comes out of the cabin, comes down the hill and the credits roll. I guess that now, almost 40 years later, that poor Anglo-henchman is still behind the cabin, waiting for them to come out.
Character mistake: When Vallian prepares to leave the homestead, McKaskell asks him how his chest wound was. Vallian was shot low on the right side, just above the gun-belt, and McKaskell, who removed the bullet, was quite aware of the location.
Factual error: When the riders are watching the wagon train, in the background you can see a communication tower with conical speakers.
Continuity mistake: When the church bell is rehung and struck, it goes from shoulder height to well above head height, then back to shoulder height in subsequent shots. (01:28:15)
Other mistake: Bandoleer rounds don't fit any weapon in the show. When Pierce tries the Gatling gun, there is no magazine in it.
Revealing mistake: As Jango fires the machine gun, the ammunition chain hanging from it is loaded on both sides, and it doesn't move. Also the belt has different sizes of cartridges in it. (00:45:30)
Factual error: The cavalry sing Low Bridge (or Fifteen Years On The Erie Canal) as they trek across Texas in 1879. This was written by Thomas S. Allen in 1905 during the time the Erie canal was switched from mule power to engine power. (00:49:00)
Continuity mistake: At the start of the train chase Tonto blows the whistle as he passes the bad guy who says "shoot him you idiot". The soldier opens fire with the machine gun and Tonto is suddenly back in front and passing him again. (02:03:35)