Plot hole: In the beginning of the movie, year 1865, Thomas Gates is asked to decode the playfair cipher for the K.G.C. This is later found and decoded by Ben Gates, who discovers "Laboulaye Lady" to be the answer. In the scene when Ben and Riley go to France to see the Statue of Liberty, there is something written by Laboulaye, ending with the year 1876. As that writing was only added in 1876, Ben Gates couldn't have referenced it in 1865.
Continuity mistake: When Ben Gates and company first examine the Booth diary page, they notice a few of the digraphs relevant to the cipher. After he says to flip the page, pause it and notice the digraphs that are visible. They are: ME IK QO CQ TE ZX. Later, when Ben discovers that the key to decoding the cipher is DEATH, Riley inputs the keyword into his computer. Pause it when it shows his computer screen. The various digraphs that they have input are nowhere close to the ones they discovered on the page. They are: QF JU WJ AK EH. Not even the same amount of digraphs, no less. The results are larger too. The entire interface is different for the two shots.
Factual error: In the scene where Ben and Abigail are using the service lift to get to a different floor in Buckingham Palace, Ben presses the button on the exterior, then shuts the door. This is inaccurate as, with that type of lift, pressing the buttons when the doors are open does nothing. The lift can only move if the doors are closed when the buttons are pressed.
Visible crew/equipment: At the last scene when Riley Poole gets in his Ferrari, you can see the camera man in the reflection by the head rest of the seat. You can see a black dot moving. That's the camera man's head.
Continuity mistake: When Ben and Abigail are examining the Resolute desk at Buckingham Palace, Ben starts opening the drawers and discovers the code option numbers on the underside of the drawers for the first time. When he does this, in the shots of the underside of the drawer, Ben is pulling the drawers out almost all the way, but in the shots from above, he is barely pulling the drawers out at all.
Revealing mistake: When Nicolas Cage meets the president in the hangar and the president hands him a newspaper containing an article clearing Cage's great-great-grandfather's name, the text of the article in the center top of the newspaper in that scene contains the same body text as the article to the right that's titled "Family Saved."
Continuity mistake: In the car chase in London, when Ben throws the plank into the Thames the Range Rover is missing the bumper and stops when knocking over a roadworks sign. The next shot shows the car far from the sign, with the bumper perfectly back to normal.
Continuity mistake: In the first film, John Adams Gates (Christopher Plummer) tells his grandson, young Ben, about how a boy named Thomas Gates learned about the Templar treasure from Charles Carroll in 1832. John refers to Thomas as "my grandfather's grandfather," making him Ben's Great-Great-Great-Great-Grandfather. The adult Thomas Gates is in the prologue of the sequel deciphering Booth's diary in 1865. His son, Charles, is said to be the grandfather of Patrick Gates, played by Jon Voight. That would make Thomas only Ben's great-great-grandfather, which another character refers to him as later in the second movie, which in turn makes Thomas Gates just the grandfather of John Gates. Either John Gates' memory is fuzzy in his old age or two generations of Gates men disappeared from the timeline. Perhaps John meant to say it was Ben's grandfather's grandfather, which is how Thomas is related to Ben in this movie.
Factual error: When Ben and Riley are in a reading room in the Library of Congress, they have books about the architecture of buildings, as well as books about security and such. However, the particular reading room they are in contains books about Social Sciences, and to order books from a different area, it takes a really long time. They would have been in a different reading room that contained books about their subject.
Factual error: While the group was in the gold cave, Riley helps himself to one of the gold bricks, which is larger than a "standard" gold brick, and is roughly three inches thick, eight inches wide, and about twelve inches long. A brick of gold this size would weigh around 250 pounds, which would make it nearly impossible for Riley to carry around, even in a backpack. Even if it were ten carat gold in the brick, it would still weigh over 100 pounds.
Continuity mistake: Just after Ben mentions Montesquieu to the French policeman, the other policeman's head changes position between shots. (00:21:55)
Other mistake: During the car chase in London, when Ben almost hits the dogs, we see one dog running up to the car and licking the backup-camera. However since the camera is actually mounted above the license plate, it's impossible to reach for a dog this size.
Factual error: In April, any lake in South Dakota is freezing cold. And it goes without saying that you don't have to be in cold water very long for hypothermia to take effect; even a few minutes is enough. So why don't our heroes succumb to any kind of hypothermia when the gold chamber floods with icy lake water?
Factual error: When the group comes to Mount Rushmore, they arrive at a lake. There is no lake close to Mount Rushmore (look at Google Maps, the lake used is Sylvan Lake, which is a good 15 miles away from Mount Rushmore). Mount Rushmore is suppose to be a "cover up" for the final treasure and that would make the chamber underneath the faces itself. (01:27:05)
Suggested correction: The story-line states that Mt. Rushmore was created to hide the clues to the treasure, not hold the actual treasure.
But they climbed over Mt Rushmore to view the lake which is in a different direction.
Continuity mistake: During the London car chase scene, Nicolas Cage throws the wooden artifact from the car into the river. The bad guys in the Range Rover then stop, colliding with some roadworks, although in the next shot the car is suddenly a few metres away. (00:42:30 - 00:43:00)
Factual error: When reviewing the picture having been caught driving through the traffic camera in London, the speed the car was travelling at is displayed in km/h. In the United Kingdom speed limits and fines are in miles.
