Factual error: As Ben is clinging to the staircase while it is falling apart, there is a close-up of a nail being pulled out of the wood. This nail is round-headed, rather than square as it would have been over 200 years ago. It's also shiny instead of rusty, which indicates that it's galvanized. Galvanization as an industrial, metal-preservation process was not patented until 1837, and was not used in building materials until well into the late-1800s. Since the film states the staircase was made by "the Founding Fathers, " and there was no galvanization of iron nails in any industrialized nation in 1780s-1830's, this is a huge anachronism.
Factual error: The sun's location horizontally changes throughout the year. Because of this, Ben, Abigail, and Riley shouldn't know where the shadow is falling, horizontally.
Continuity mistake: When Ben is first confronted at his father's car by the FBI, you can see Chase and Riley in the background standing there and then turning around and leaving. Then as they arrest Ben against the car, you can see Chase and Riley just turning the corner, noticing Ben being arrested, and leaving.
Factual error: When Ben finds Charlotte buried in the ice, he would have encountered solid, thick ice. The small pick-ax he uses seems to easily break through the ice. Also, he seems to be digging through packed snow, rather than thick ice, which is indicative to the Arctic ice shelves.
Character mistake: Once the characters are in NYC, Nick states that Wall Street was originally a wall (correct) built to defend against the British (incorrect.) The original wall was a wooden palisade built in the 16th Century to defend the colonists against invading natives and to prevent livestock from wandering uptown.
Continuity mistake: When Ben puts his tool belt on the conveyor belt to go through the X-ray machine, we see the gloves are on the left and pointed down while the red, rubber encased plyer handles are approx. in middle leaning slightly to the right and no space between the plyer handles. As we watch the tool belt go through the X-ray machine, the gloves are on the right side with the plyer handles almost directly above the gloves, both handles visible and the rest of the belt all to the left.
Continuity mistake: When Ben ducks into the Gift Store, there is a blonde lady in a black dress standing at the counter between Ben and the door. She steps forward out of the picture as Abigail goes by. Then as Ben starts to turn to leave the store you see her arm come back into the picture. But as Ben walks by that part of the store and the clerk says to Ben, "Are you trying to steal that?" the lady has disappeared.
Continuity mistake: This has to do with Ben getting Abigail's fingerprints off the champagne glass. When he hands her the champagne glass, her fingers are positioned on the lower half of the glass. Later, when Ben "takes" her thumbprint off the glass, he takes it from a much higher part of the glass.
Factual error: In the scene under the Trinity Church in New York, on the wall are two metal support beams in the shape of an X. There are bolts and washers securing the beams. Judging by the elevators that are operated by pulleys, there should be wood with square nails in the time period which the underground passage was built. Seeing the total state of disrepair in the underground elevator shaft, it is extremely unlikely that any updates/repairs were made significantly later than the time it was originally built.
Continuity mistake: The actor who plays Ben as a child has brown eyes, but Nicholas Cage has blue eyes.
Continuity mistake: After Ben And Riley climb down into the smuggler's hole and are scrambling to get away, Ben grabs Riley and throws him through a hatchway. Riley lands in the snow with a wall next to him, on the screen's left side. Right before the blast, Ben dives (is thrown) facedown in the snow next to Riley but the screen is a mirror image of the previous one because the wall is now on the right of the screen and so is Riley.
Factual error: When Dr. Chase receives the Washington campaign button from Ben Gates, she immediately picks it up with her bare fingers and rubs it with her thumb. An expert collector would *never* handle metal objects with their bare hands like this, as the acid on the fingers will corrode the metal. Cleaning the coin afterwards is also not an option, as this presents an even higher damage risk. See http://www.stujoe.com/content/view/30/34/ for more details.
Revealing mistake: When the stairs built on the walls of the dumbwaiter shaft start to collapse, Riley makes a jump onto a stable one. In the first shot of him jumping you can see a thick stunt wire attached to the back of his shirt.
Character mistake: At the gala, Ben describes to Abigail how the Founding Fathers would have been hanged, beheaded, drawn and quartered, and had their entrails burned had they lost the war. However, only hanging and beheading were acceptable practices in Britain at the time; Ben's information is off by several decades.
Continuity mistake: In the catacombs under Trinity Church, the lift Ben and Abigail are standing on falls. When it jerks to a stop, Abigail falls and Ben catches her. The lift is stationary at an angle. However, in the next shot, the lift is swinging forwards, allowing Ben to throw Abigail to safety.
Factual error: Ben, Riley, and Abigail are driving into Philadelphia at sunrise to go to the Franklin Institute. They are shown driving west on the Ben Franklin Bridge. The sun is actually setting in the west behind Philadelphia, not rising.