Continuity mistake: At Isengard, when Pippin recovers the palantir, in two shots it's large enough to fill both of his hands, so that he has to spread all of his fingers to hold it. In the next shot of Pippin and Gandalf, Pippin raises one hand holding the palantir and Gandalf quickly takes it. In this particular shot, as Pippin hands the palantir to Gandalf with one hand, the circumference of the palantir is noticeably much smaller (while still in Pippin's grasp), than it was in the previous shots.
Continuity mistake: After Gerry gets smacked in the face by the 'broken' suspender clasp, we see the silver clasp land under the dresser. Yet, when he's moaning and lifting his leg to get onto the bed, we can actually see the clasp still intact on the front suspender that came loose, which is dangling right behind him (just look between his legs). Of course, in the next shot, that clasp is gone. Since the silver clasp is one of the plot points, this is bizarre to say the least.
Continuity mistake: When John and Catherine are in the hangar at the runway, the Cessna's tail number is N3035C. When the plane is shown in the air, the number is N3973F. When they land, the tail number has changed back to N3035C.
Continuity mistake: In the bedroom scene the girl is holding a clear cup full of beer. The camera goes off her and when it comes back she is holding a blue cup. The camera goes back off her then on her and the cup is clear again.
Continuity mistake: When Sam is in his bedroom, after he finds the Cube sliver it falls and dramatically burns a hole through the floor into the kitchen. But Sam's bedroom is over the living room (there is nothing on the ground floor below Sam's elevated bathroom, and in the first movie Jazz hides in this open space), and the kitchen is actually located between the den and dining room, at the other end of the house. If they were to follow the actual floor plan of the house, the Cube sliver would have landed in the area of the piano in the living room, but where would the fun have been in that?
Factual error: The idea that humans only use 10% of their brain is a widely-circulated myth that has been debunked by neurological science many times over.
New this week Other mistake: When the Kingsmen are looking on-screen at the dossier of the princess, the attached photo of her is just a screenshot from the earlier scene where she is at the dining table with Valentine and the Scandinavian prime minister, just before she is imprisoned. Her photo was not taken at that point, and couldn't have been attached to her private file.
New this month Continuity mistake: When Stuart is leaving the building, he enters a previous generation Mercedes Benz S Class. The next couple of shots where he is being followed by Bryan shows the newly redesigned S Class.
Continuity mistake: When Penny prepares to lay down on the ice next to Judd, the back of her sweater is already wet from previous takes.