Revealing mistake: The final scene is filmed in Brant Rock MA, and the weather is blatantly CGI. If you notice almost everyone is bone dry in a supposed driving rain storm. Look especially at the character perched on top of the submarine tower. For contrast note the "pizza delivery" scene where it is raining heavily and everyone involved is soaking wet.
Revealing mistake: Fight in the toilet of the Paris nightclub: the presumed Lark rips out the sink's drain and begins assaulting Tom Cruise with it; Walker intervenes holding him, but the nimble Asian does a flip and brutally tosses him to the ground. As Henry Cavill is bent over before being snapped to the floor, on his back, you can definitely see a protective pad through the jacket. (00:31:52)
Revealing mistake: During the police chase with Gabriel on his motorcycle, he stops and turns to start shooting at one of the cops. By appearances, Gabriel is using a standard Glock which had a magazine capacity of 15 rounds. He has no extensions on it at all with the handle and magazine visible. Yet he proceeds to fire the gun 33-35 times at the cop car without reloading and in continuous fire. (00:57:55)
Revealing mistake: When Claire hangs up the phone at the start, the phone is actually off. (00:10:30)
Revealing mistake: Just after Proxima Midnight and Corvus Glaive land in the train station, there is a wide shot where they begin approaching Wanda and Vision. In the wide shot, their shadows do not appear to match up with each other, despite being under the same lighting. Proxima Midnight's shadow is positioned in front of her and is quite heavy, but Corvus Glaive's shadow is positioned more to his left and is much lighter than Proxima's. (00:40:20)
Revealing mistake: During the big shootout on the freeway at the end of the movie, there is a camera pan over all the cars stopped in traffic. There are no people in any of the cars. The shot is so high that you would still be able to see people crouched down if that was the case. (01:56:47)
Revealing mistake: As Will and Ben are wrestling for the gun, it goes off, shooting Ben in the chest. When you hear the shot you can see the gun is lying on Ben's chest with him holding it, and it's pointed pretty much at an exact 90° to his side. It would have barely grazed him at best and would have left a long scratch/cut at that angle. Yet as they get up the shot is perfectly centered on his chest and round as if it was a direct shot. (00:24:55)
Revealing mistake: When Drake's henchmen are chasing Eddie on the street while he is riding his bike on the sidewalk you can see the stunt man driving for him.
Revealing mistake: When Chewy puts his hand on Han's shoulder at the end, Joonas Suotamo's finger is visible through the fur.
Revealing mistake: Near the end when the orphans are exiting the building in the bus, you can tell they practised the sliding part. There are marks in the roof of the bus from previous takes.
Revealing mistake: When the Wolf King is arriving through the elevator, there's a shot from a distance featuring Jodie Foster that wheels a chair in. You can see in it that the elevator arrow display is not moving; nobody is using them. (00:50:35)
Revealing mistake: When Orm presents the weapons to Manta as a water hologram, Manta walks right through the hologram with half of his body. This arm passes through the hologram made of water and even makes a splash sound. However, there is not a single drop of water on Manta's completely dry clothing after this.
Revealing mistake: When the doctor with the satellite phone runs to the car, he is being chased by another member of the team, and of course the graboid. Look ahead of the graboid. The path it will take is visible.
Revealing mistake: After Robin starts to believe that the Teen Titans are in fact a joke, he gets sad and goes out a hole in the wall saying goodbye to them. He fires his grappling gun up and steps out of the wall. But his arm remains bent as he stands casually in the air to be taken upwards. There is no effect of gravity or any realistic body motion in those moment. As his weight should have had him dangle down with his arm stretched out above him and him swaying like a pendulum. Instead he appears as a stationary action figure in a single pose with his elbow bent as he's taken up.
Revealing mistake: When Velma sabotages the science project making it explode into purple goo, you can see that the vial of chemicals she tampered with simply spray around clean liquid, and the purple goo falls from above. (00:23:55)
Revealing mistake: The covering of snow was not real snow. When the trick-or-treaters are first seen, there are images of footprints (shoeprints) in the snow, but the trick-or-treaters walking over the "snow" do not leave any footprints. (00:44:38)
Revealing mistake: When Bearman and the President are running from the Russians, we see some Russian 4x4's doing a hard turn to chase them. In this shot you can see skid marks from previous takes. (01:15:30)
Revealing mistake: When Asher is shooting a bolt-action sniper rifle there's no casing ejecting from the rifle as he reloads it with the bolt. (00:48:30 - 00:49:25)
Revealing mistake: After Mel is killed, Scott drives away in a truck that they were just hiding behind during the shoot out. But there is not a single bullet hole or sign of damage to the truck.
Revealing mistake: Parzival heads back to the Halliday Journals to watch the scene of Halliday and Morrow parting ways again. There is glass between him and the scene and some camera angles show Parzival through the glass from inside with the scene reflected on the glass. However the reflection is wrong. Morrow is standing on the right with Halliday on the left, but when showing their reflection in the glass, their positions are not reversed. (00:23:45)