Factual error: As John and Mrs. Rogers are out for a buggy ride, Mike Sweeney comes up on them in his horseless carriage. You can see the Horseless Carriage plate on the rear of his car. These plates were not issued back when the film was depicted. (00:42:00)
Factual error: Gilliam is walking Mrs Rogers to church and whistling the tune "The Entertainer," by Scott Joplin. However the film is set in 1901 and that music was first published in 1902. (01:12:00)
Continuity mistake: A couple of times in the movie, the camera pans to John Wayne, and his hair is parted on the wrong side. (Reverse editing flaw).
Visible crew/equipment: From the video version: When Books (John Wayne) is shot in the back by the bartender, you can clearly see a rope fastened onto the heel of his boot that is being pulled to help him stumble and fall onto the floor as the second shotgun blast hits him.
Factual error: The opening montage depicting Books's past exploits mentions a Colt .45 and shows a single action Colt revolver being fired. The date indicated on the screen is 1871. This revolver was not manufactured until 1873.
Revealing mistake: In the closing scene, you can see the modern curb & sidewalk have been covered with dirt.
Continuity mistake: When Books falls in the bathtub, Mrs. Rodgers goes in to help him, and about three seconds later, he emerges from the bathroom fully clothed in his robe and a towel around his neck.
Visible crew/equipment: When Books places a gun in the writer's mouth and says "Make like that's a nipple" you can see the shadow of Bond (Lauren Bacall) waiting on the stairs to come down into the scene.
Continuity mistake: In the bar room fight, Books fires three times, then once with revolver in his right hand. Gilliam picks up that same gun and fires three more times - a total of seven rounds from a six-shooter.
Continuity mistake: In the scene where Books and Gillam share a bottle of whiskey, as the camera changes angles the bottle label is always away from the camera.
Continuity mistake: When Books is in the barber shop talking to Mr. Beckham the undertaker, in different scenes Books' tie is either inside or outside his vest.
Continuity mistake: In the beginning of the movie Jay Cobb sitting in his creamery coach reaches for his gun in his holster on his left side. In the final scene when he shoots at Books he's right-handed.
