Visible crew/equipment: In the shot where Faris is running to Evans's room to get him away from his one-night stand, as she passes the staircase you can see a shadow with movements that don't coincide with those of Faris. Deductive logic can be used to determine that this shadow is that of a member of the crew.
Other mistake: In the scene near the start as Will Atenton is being driven to his house by the property agent there is a close up of the car which shows a snow covered bonnet therefore the car would not have been driven very far as the engine was not warm.
Continuity mistake: When Alan is taunting Michael about selling door knobs and Michael's back is against the door frame to the dining room, the dining room is dark; both chandeliers are off. All four characters are in the living room but as Michael responds to Alan's taunts, the lights are on, even though no one entered that room and Michael's hands were in his pockets during the exchange.
Continuity mistake: Three-quarters into the film, Jacob brings Rosie, the elephant, to Reece Witherspoon's tent. Her husband, August, appears and seconds later there is, out of the blue, a cigarette between his fingers.
Continuity mistake: When Conan first fights Remo, Conan places a blood stain on his forehead by pressing his sword to it. Remo then runs off, and Conan gives chase immediately, pausing only to get Tamara on his horse. The stain is still there when Conan mounts his horse. The next time we see them, Conan and Tamara is still chasing Remo, but now Conan's face is completely clean. It is highly unlikely he would pause in pursuit of one of his father's killers to wash his face. (00:47:55)
Factual error: The security guard in the bank is carrying a revolver as a sidearm but has semi-automatic magazine pouches on his duty belt.
Continuity mistake: At the beginning of the film, protesters chase Harold through downtown traffic until he dives into his friend Todd's vehicle; whereupon the protesters urinate on Todd's windshield and splatter fecal matter across his driver's side window. For several scenes thereafter, the fecal splatter repeatedly changes shape, orientation and quantity on the side window, actually gaining mass in some shots.
Factual error: Danny Greene has a bomb placed in Shondor Birns' car. As Birns is waiting to cross the sidewalk, the pedestrian walk-don't walk sign is a modern digital sign, that was not around in 1975.
Continuity mistake: Late in the movie, when Anya says goodbye to Patrick, she takes off her wedding ring and puts it on the table before leaving the café. In the next scene, her wedding ring is visible on her hand throughout her call from the phone booth.
Continuity mistake: Towards the end of the movie, the kids run upstairs to get changed into their PJ's. However, the girl, Blythe, is already wearing her PJ's and a second earlier was wearing her skirt, blouse and tights.
Continuity mistake: In the scene where Lily is hiding behind Thomas' computer desk, she uses her little Eiffel tower necklace to put inside the socket to short out the power. When she goes to put it in, you can see the computer is plugged in on the bottom socket. After a really quick cut scene, the computer is now plugged in on the top socket. (01:05:00)
Continuity mistake: The designated Pope has just been visited by a physician. Three cardinals want to take a stroll outside for some sweets and arts. One of the cardinals stands and rebukes them; you can see that the cross on his chest has its chain caught in a button of the vest. During the rest of the scene the chain is caught in that button in the closer views and is loose in the wider angles. (00:23:50)
Other mistake: The protagonist uses his belt to temporarily fix the movie projector. He has to keep his pants on with his hands, but that's only until he has to grab an object and the pants do drop. Then he is still belt-less but the gag ran its course and his pants are not falling off anymore, once was enough.
Continuity mistake: Dr. Mario Tirelli at the beginning of the movie enters the clinic where he works. A blonde woman walks in the opposite direction and exits through the door as Tirelli briefly hails a nurse. At the cut, Tirelli is in the same spot as before (nothing changes in the background) but the blonde is back and with still a way to go before the door, and the nurse is far back too, with the doctor's hand not moving to greet her, in a different take entirely. (00:03:00)
Factual error: In his crude attempt to replicate the Human Centipede surgical procedure, Martin employs several handyman tools, including a carpenter's staple gun (using T50 staples as sutures). Problem is, carpenter's staples would never join soft human body tissues, they'd pull right out with little effort (T50 staples only join to very solid base materials, such as wood). Martin's victims, hysterical as they were, could have freed themselves from the T50 staples almost immediately.
Other mistake: When the evil warlock breaks his way out of the condemned house, he uses explosives to escape, but for some odd reason, the door is the only thing affected by the explosion.
Continuity mistake: After Sarah finds her father in the bedroom and goes downstairs to get help, the blood pattern on her shirt/upper breasts changes. While the movie is edited to look like one continuous shot, it was filmed in bits and pieces, and the blood pattern was not consistent in some of the shots, it seems.
Deliberate mistake: The driver's side mirror would not be able to capture the view of the store that Monique is robbing - the mirror is slightly angled towards the rear of the car, plus Arthur's car is parked too close across the street. (00:00:33)
Revealing mistake: When Anna's looking at her reflection in the mirror she starts rubbing her face vigorously. Look at her right cheek and you'll it's red before she rubs, result of multiple takes.
Continuity mistake: Kate's stockings change colors, from black to beige, while she's running late to work. (00:12:10)