Back to the Future Part III (1990)

Revealing mistake: When Doc jumps from the horse to the train, right after he hurries Marty, the man on the horse is an obvious stunt double for Michael J. Fox.

Continuity mistake: When Marty holds the temperature-meter and warns Doc to put the yellow log inside the firebox, his finger suddenly disappears between shots.

Continuity mistake: When Buford hangs Marty, he puts the rope around his neck once. In the close-up the rope goes around twice.

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Continuity mistake: When Marty and Buford duel, Seamus' distance to the bartender keeps increasing / decreasing randomly between shots.

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Continuity mistake: When the train hits 70 mph the chimney explodes to pieces. When the bar that Clara holds onto breaks the chimney reappears.

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Revealing mistake: When the train pushes the DeLorean and hits 70 mph Doc tries to grab Clara. In the wide shots (where we can't see his face) his coat whips, but in the close-ups where we do see his face the coat flutters, revealing that the train was going much faster with the stuntman.

Sacha

Revealing mistake: At the festival, after Marty is given the gun he encounters Seamus and Maggie. Due to the Vistaglide camera effect where Marty was later added to the scene, she is unable to look at where Marty is supposed to be. This is very noticeable when Seamus says "buffoon" and Marty turns around and starts to walk, but Maggie keeps staring at where he was. Also when the scene ends and she looks at Marty and warns him to watch for the future, she's totally missing the spot.

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Continuity mistake: After the festival, Marty wakes up and grabs the gun belt, which is missing a bullet. When he mimics in front of the mirror the bullet has magically appeared.

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Continuity mistake: When Doc holds the telescope and tells Clara that he'll fix it, right when they date at the festival the position of the telescope changes between the front and back shots.

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Continuity mistake: After Clara pulls the emergency pull cord she jumps out of the train with her gloves on. From the immediate opposite angle her hands are bare.

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Continuity mistake: When Marty is about to duel against Buford he is inside a house peeping through the window, pulling the curtain open. The position of his hand and the opening of the curtain differs between shots.

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Continuity mistake: Buford spills the spittoon on his shirt, but when he lassos Marty his shirt is dry and clean.

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Continuity mistake: When dueling, Marty's holster belt on the floor changes positions between shots.

Continuity mistake: After the bartender prepares the wake-up juice, the two men by the table behind, plus the smoke coming out of the ashtray, disappear. When Marty pours the liquid the men reappear.

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Revealing mistake: When Marty pours the wake-up juice through the funnel into Doc's mouth, in the close up the funnel is straight, but we can't see Doc. From a different angle where we do see the funnel stuck in his mouth, check the right side of the screen: The funnel is skewed (and seemingly it must have a tap) and the liquid is falling out in large amounts to avoid the actor from drinking it.

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Continuity mistake: Just when Marty parks inside the cave to hide from the Native Americans, one wearing a war bonnet jumps over the mount. When the angle changes, the man is gone and has been replaced by two riders with no war bonnets.

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Continuity mistake: After Doc meets Clara he and Marty watch a tombstone. Doc grabs the picture and says "my name has vanished!" The way he holds the picture differs between the first and second shot.

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Continuity mistake: When Buford duels Marty, the people behind him differ between shots. In the shot outside, there's a tall man with a blue shirt, a young guy and a man with a white shirt. From the angle shot inside the bar, the number of people behind the group has doubled, the man in white is gone and a woman has magically appeared standing next to the man with the blue shirt.

Sacha

Continuity mistake: When Doc passes out after drinking whiskey, he falls face down against a table and his back gets wet. When the angle changes it's dry and covered with glass.

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Continuity mistake: At the bar Doc says that in the future people run for fun. When the guys playing poker laugh at him, the bartender magically appears next to them between shots.

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