Deliberate mistake: In the scene where Emmet drives to work, you get Emmet's view of the dashboard with his hand switching on the radio. The car at that moment has no front window, perhaps to make the car look bigger from the inside. (00:04:50)
Continuity mistake: In the first encounter with Brigham, Cage has one button on his jacket undone during one shot, and in the next shot it is buttoned up.
Continuity mistake: By the end of the movie, when Lucy is sitting in the chair and her skin turns black, we can see her arms slowly turning black as well. When camera cuts away and shows Lucy from behind, her arms are naturally white again.
Other mistake: When the blue van rolls over, and they turn around to go pick them up, they park like 20-30 feet from the van for no reason, instead of right by it, seemingly just to have a tree block their path, then decide to run into a church with really big stained glass window and wood pews while a fire tornado is just outside. Rolling the van back upright, all the TVs and equipment inside the van seem to be working just fine.
Deliberate mistake: Despite taking place for at least three years (prior to the arrival of Thomas) in an isolated post-apocalyptic setting, the boys in the Glade have professional looking hairstyles, not the least of which are Minho and Gally, who both have short hairstyles that look evenly cut and professionally maintained.
Revealing mistake: When Viggo pushes the car off the edge and it hits the ground, as it rolls you can see that the engine/transmission, drive shift and tank have been removed. (01:26:00)
Other mistake: At end of movie where there are captions describing how the lives of everyone turned out, for Louie it says "after years of SERVERE PTSD..." instead of "severe." (02:10:25)
Factual error: After fixing Emily's car, James explains to her that someone must have poured sugar in her gas tank, and besides cleaning the gas tank, he will also have to replace the fuel filter and the carburetor. That would simply not happen: As several tests show, 'sugar in the tank' is a complete myth that will not cause any engine problems. If anything at all would happen, it would clog the fuel filter, but never destroy a carburetor. And even if it would, it could not on a Emily's car - since it's a Fiat 500 and (like all modern cars) it has fuel injection, and does not even have a carburetor. (00:14:00)
Factual error: When they show Alex's partner in the hospital his heart rate is showing 35 on the monitor. His heart rate is not that low from the EKG pattern.
Continuity mistake: In the scene where Corvus kidnaps Cassia and is racing through the city on his chariot, the street he is travelling down is completely devoid of rubble, bodies, and anything else that was already shown to be strewn across all of the streets.
Factual error: When Magneto enters RFK stadium, a groundskeeper is lining a baseball field. RFK stadium did not host baseball in 1973, as the Washington Senators had moved to Texas to become the Texas Rangers after the 1971 season. In 1973, the only team playing in RFK regularly was the Washington Redskins of the NFL. In addition, the Paris Peace Accords were signed in January of 1973; so there wouldn't be green grass inside the stadium, regardless of what sports were being played there.
Factual error: During the final fight, Liam Neeson jumps down an aisle to pick up the pistol that is hurled from the floor upwards in the air and shoots the villain in the head. The problem here is with physics. The plane was in radical descent moments before. The pilot eventually brings up the nose. At that moment, the gun and Liam Neeson himself would have been pinned to the floor.
Continuity mistake: In the beginning when Morton and Greg meet the drug dealers at the harbor, look at the big rig that is hooked up to the trailer. In the first few shots the truck brand is a Volvo, then when the truck drives away, it's an International.
Continuity mistake: When Jeanine looks at Tris' tattoo, there is hair covering the top of her ear. A few shots later, the hair covering her ear is suddenly behind her ear with only a strand of hair left over it. Then the hair is suddenly back to covering her ear as Jeanine goes to leave. (00:48:50)
Continuity mistake: During Stoick's funeral Hiccup first shoots an arrow towards the ship and then the other characters draw their bows. Gobber is not shown as he is further away. In the next shot where they shoot their arrows, Valka and Eret are suddenly further apart from each other and Gobber has moved closer in between them. Eight arrows are shot simultaneously, but only seven arrows rain down.
Other mistake: In the scene that Callaghan's daughter went into the portal, there is a track for the capsule to go into the first portal, but there was no track for the return portal.
Continuity mistake: The necklace Stefan gives Maleficent appears and disappears as she is flying around the Moors. This is just after she gets the true love kiss.
Continuity mistake: In the scene where Ava shoots Damien, she has no bra under her sheer nightgown in one shot and then has one when she goes to the window in the next.
Other mistake: At the end, when she's writing the email, she enters a subject line first, but then when we see a closeup of her clicking the "send" button, the window title says "untitled message." That would have been replaced by the subject when she wrote it.
Continuity mistake: When Justin is disguised with the dread locks, one of the body guards gets into a fight with him. Justin is punched hard in the face in slow motion, the impact of the fist shown to hit below Justin's cheek on his jaw. Yet the next day Justin has a huge red mark above his cheek on his temple.