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: 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: Cottontail gives Tom a wet Willie. However Tom reacts before Cottontail touches 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: When Scott is fighting Ghost, as Pym is planning to dive, Ghost throws Scott through a wall and you can see the braking cable around his/the stuntman's waist and across the floor. (01:16:48)
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: 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)
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: 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.