Factual error: We see how the accident-prone Wilton Parmenter was a soldier at Appotomatox during the Civil War when he sneezed. Union soldiers mistook his sneezing for a call to regroup and charge, winning the battle. Wilton Parmenter was awarded the Medal Of Honour. Accident-prone, even in his moment of glory, when the medal was pinned on Wilton's chest it pierced his skin, drawing blood. Wilton was therefore awarded the Purple Heart, becoming "the only soldier in history to get a medal for getting a medal." This was not possible, for the "Purple Heart" (or "Badge Of Military Merit", to use its proper title) awarded to US soldiers wounded in action, was only instituted in 1932. (Before somebody corrects me, George Washington did institute the award for some distinguished combatants during the War Of Independence, but it was never awarded during the nineteenth century, and revived in 1932).
Continuity mistake: When the Indian agent is killed, a very 20th Century rubber-tread shoe print is visible in the dirt beside him. When Cheyenne arrives and finds the body, though, the footprint has disappeared.
Old Scores - S2-E17
Continuity mistake: In the scene where Shaddock is shot in the arm you can see that the wound moves from near his elbow to his shoulder.
Other mistake: The Lakota is attacking a small group of men. One is face down on the ground, and he lifts his head to cut his throat. In the background are two cowboy actors joking and twirling their guns. One drops his gun and picks it back up. (00:20:43)
The Crossing - S1-E4
Factual error: The Dutton camp as well as Shea Brennon and Thomas are using modern thin Teflon/non-stick coated coffee mugs/pot.
Visible crew/equipment: As the old Indian sets fire to burn his dead son, he walks towards Cain and on the left you see a fire extinguisher. (00:10:04)
Shot the Head off a Snake - S1-E5
Factual error: Frank Griffin makes a reference to Burma Shave in the 1880s. Burma Shave didn't appear until 1925.
Visible crew/equipment: There is a shot of the outside of the tavern (used in several chapters) where Zorro jumps towards Tornado. As the two walk away, a hand can be seen hiding behind the wall where Tornado was standing.
Plot hole: When Ellie leaves Ft. Smith on a whiskey boat, she's just been seen with the morning sickness a day or two before. When she leaves the whiskey boat, somewhere between Arkansas and Nebraska, she says she's pregnant but is not showing at all. Even the snaggle-toothed frontier weirdo played by Steve Buscemi remarks that, "You ain't gonna be havin' no baby fer a while yet." The day she gets to Clara's, near Ogallala, Nebraska, she has the baby. Pregnancy lasts nine months. Morning sickness usually begins at about six weeks into it. Ft. Smith, Arkansas, to Ogallala is 561 miles. Even just walking three miles an hour for eight hours a day, one could make it in less than a month. But going via boat and mule-drawn wagon took her over seven months?
Factual error: In this final made-for-TV mini-series of the 'Lonesome Dove' franchise (the one with James Garner as Woodrow Call), they show the crazy renegade teenage killer hanging Judge Roy Bean from the beams outside the front of his own store/courthouse. Bean died peacefully in his bed on March 16, 1903, after a bout of heavy drinking in San Antonio.
Continuity mistake: During the ambush, young Jack, on horseback, takes off after the wagon which is carrying his wounded fiancé. The chase is long including a cut away and yet the wagon winds up only yards away from the ambush where the chase began.
Other mistake: Lucy Lawrence enters the stage depot in Bentonville and introduces herself as the new schoolteacher. A young boy exclaims, "School! Phooey!" Mrs. Lawrence says, "Well, school isn't all reading and writing and sums, Edgar." She had no way of knowing his name.
Character mistake: When the gang is watering the horses, Chris walks over to meet Mary's man friend (whom she introduces as an old friend of the family) and the mystery man tells Chris that he'd proposed to Mary long before 'Frank' when Mary's late husband was Steve.
Factual error: The show is set in the 1860s. However, in several episodes, trail boss Gil Favor can be seen wearing Wrangler jeans. The Wrangler brand was not introduced until 1947.
The Kid from Silver City - S3-E10
Continuity mistake: Roy is visited by a deputy marshal who is looking for the son of a local storekeeper. When the two men leave to visit the storekeeper, Roy leaves his hat on the kitchen table, but when he enters the store the hat is on his head.
Continuity mistake: Conchita slaps Cash across the left cheek, which he's rubbing as he returns to his office. In the next shot, as he comes through the door, he's rubbing his right cheek instead.
Visible crew/equipment: When Bat arrives at the hotel to escort Lucy, the shadow of the microphone and part of the boom rigging are visible on the wall above the door. (00:17:30)
Visible crew/equipment: In the wall mirror behind Clint Eastwood, the shadow of the boom rigging can be seen moving up and down. (00:08:00)