When the stagecoach is ambushed, one of the men handling the Gatling gun is shot and falls off the coach, a few cuts later he's back by the gun and very much alive.
The first night camping out, Ben is sitting in the cold night air with just his shirt and vest on. The next morning he is again wearing his jacket. This is rather difficult to explain since he was supposedly handcuffed throughout the night.
At the beginning, when Dan's son William lights a match to see at night, the match burns very slowly and irregularly, varying the burnt length. When he puts it out, only the tip is burnt despite it being lit for about 60 seconds.
In the fight with the railroad workers, one of the workers has a badge on the left lapel of his coat. When they are shown meeting Wade's gang in the tunnel, the badge is on his right lapel. When he is shot, it is again on his left lapel.
After the stage coach tips over Charlie Prince goes over and picks up Byron McElroy's shotgun, he breaks it open to check it. The scene then starts from another angle still showing Charlie Prince and he breaks the shotgun open a second time.
When the train is leaving the station, the engineer whistles three times. Three whistles means the train is going to back up. One whistle means it will go forward.
No hangings or executions would have taken place at Yuma Territorial Prison, so when they say they are taking Ben Wade to the prison for execution, it was incorrect. Yuma Territorial prison was for inmates to serve out their sentences and did not have a death row of inmates awaiting execution. Those inmates would likely have been sent to a county jail facility while awaiting their hanging.
In the end credits writer Halsted Welles is incorrectly listed as Haslted Welles.
At the hotel, Butterfield slides a badge under the hotel door, yet after the door is opened the sheriff and his deputies are all wearing badges. However, the badge Butterfield slides under the door is a deputy badge for Dan; hence, Dan throwing it back to the sheriff when he leaves.
Anesthesia had been in use for over 25 years before 1880. But it was still expensive and difficult to get, especially in distant towns. Furthermore, though Doc Potter is a very organized doctor, it is indicated that for a long time, most of his patients have been animals. And while the preservation of livestock and service animals was important enough to take pains to take care of them, anesthesia would not have been considered necessary for them (in the days before the ASPCA, it would have been considered an impractical waste.) Therefore, it is logical to assume that Doc Potter, having had few or no human patients in recent memory, would not have any readily available. It is also likely that McElroy would have refused it anyway.
Dan tells his wife that he 'has been standing on one leg for three years'. This is metaphorical and a play on words at his own expense. He is referring to how long he has been trying, unsuccessfully, to maintain the farm and support his family in the Arizona territory. He is not referring to how many years have passed since he lost his leg in the Civil War; the screenplay clearly states that the film is set in 1884.
Before the gang set the stage coach on fire, one upward-angled shot of Charlie Prince shows that there is no roof on the stage. The lawman "trapped" inside could have exited through the large rectangular hole at any time.
SPOILER. In one scene, Wade is pointing a shotgun at Evans, Doc and others. Evans' son sneaks up behind Wade, aims at Wade's head, and demands Wade drop the shotgun. When Wade hesitates, Evans' son fires a warning shot just to the right of his head. When the shot changes to a perspective behind the son, you can see that the warning shot he just fired just to the right of Wade's head would have probably hit Doc, Doc's horse, Evans, or one of the other good guys - they were standing just to Wade's right.
When Wade, Dan, and the group are escaping through the tunnels after Doc hits the man with the shovel, Doc gets shot in the back but there is no bullet hole in his jacket. You can see the blood from the front when he dies.
The portrait of Evans drawn by Wade has a incorrect angle of view per where they were seated. In fact, to draw that portrait, Wade would have to sit in the opposite corner of the room.
After Byron is shot in the stomach, he is taken to a doctor for emergency care. But rather than having a simple bleeding hole where the bullet penetrated, his stomach is completely torn open. This type of extreme trauma is inconsistent with a single bullet entry wound.
There are dialogue references to "gunslingers," a term which did not exist until the 1920s. Author Glendon Swarthout says at the time of the film, such men would have been referred to as "shootists," "pistoleers," or simply "gunmen."
The song that Ben Wade sings, "they're gonna hang me in the morning..." is called The Arizona Killer, and dates from 1995. It is a version of an older song, The Tennessee Killer, but even the older version is unknown before 1942.
The construction sites in Contention have dimensional lumber being used and that didn't come into widespread use until mid 20th century. As explained in the behind-the-scenes featurette, the filmmakers decided to use the unfinished buildings in the final chase sequence because they ran out of budget for set-building.
During the stagecoach robbery, modern tire tracks can be seen in the dirt in a few shots.
In the final scene where William is about to shoot Wade, a modern clothing label is visible on Wade's shirt.
In the train office, as Dan is talking to Ben in a reverse shot (focus on Ben), Dan's mouth moves but his dialogue isn't heard until after his mouth stops moving.
At the end of the movie when the train finally shows up at the station you hear the bell on it ringing. But when it cuts to the train pulling into the station you can see the bell on top of it not moving while the sound of it is still going.
When Doc Potter removes the bullet from McElroy's belly, he drops it in a metal bowl. The noise of the dropping bullet does not match up with the visual drop.
During the shootout when Ben and Dan are on a rooftop, before the camera cuts to Ben and Dan, Charlie Prince fires a shot but there is no sound when he shoots.
When in the train station, the camera angle is over Dan's right shoulder pointing at Ben; Dan is talking about his younger son Mark but Dan's lips aren't moving.
As the stage coach flips over in the robbery sequence, you can clearly see a white sandbag used while filming the stunt.
Bisbee, Arizona is portrayed as being laid out on a flat plot of land, when it is actually a mountainous, hilly town. The general appearance of the countryside shown in the film bears scant resemblance to southern Arizona, where this movie is set.
In the shots at the train station you can clearly see all of the land in the background is covered in snow. There's even snow on the tracks. Not only is it evident that it's spring or summer time but there is a drought. Even though Contention is a distance away from Bisbee there would have never been a drought at one town while there's a blizzard at another.
The outlaws are after a stagecoach which they know carries a Gatling gun. They have cleverly set up a way to stop it - but decide for no good reason to first chase it and get shot at, with predictable losses.
No explanation is ever offered as to why Wade's gang doesn't simply tear up a segment of the railroad tracks outside of Contention, either to prevent the train from arriving or to rescue Wade after it leaves.
In the final part of the movie Dan shoots more than 100 bullets with a couple handguns. He had no way of even carrying anywhere near that many bullets let alone shooting them. Both of his guns could carry 6 bullets each at most.
When Wade is in the process of being transported to his trial, he has dinner at Dan Evan's house. Dan seems to have no qualms with his wife, Alice, sitting right next to this cold-blooded murderer. However, after the dinner, he scolds her for exchanging a few words with Wade.
The film opens with a rancher having his barn burn by the henchman of a man he owes money to. The henchman shows his face, which is absurd since he could be arrested for arson.
During the stage coach ambush scene early in the film, two men are using the Gatling gun. One of the men is shot and falls off the coach. In the next brief scene viewed from behind the attackers, you can see two men at the gun. Next scene, just the one again. Starts approx 9 minutes into the movie.
Early in the movie, William makes the comment that "... the calvary is coming..." He should be saying Cavalry.
After Marshal Will Doane and deputies enter the hotel room, Dan says "there's five of us." But including his son William, there are six.
Wade is wearing an Australian bush hat which they did not have in the old west. Being from down under he may have asked the costume dept. for the hat.