Factual error: At the end when Ben Willis and his son have Julie at the graves, Ray shows up with a gun. He fires at Ben but there is no bullet in the chamber. Later after the fight between Ray and Ben's son Julie picks up the six-shot gun and fires 8 shots at Ben.
Factual error: In the cemetery, the skeleton of Gregory Peck's son is far too big to be that of a newborn, which it is supposed to be.
Factual error: Near the beginning of the film before James McAvoy heads up to the house for the evening meal, he is seen looking up through a skylight when a Lancaster bomber slowly flies overhead. At the time it was was supposed to be 1935. The Lancaster bomber did not fly until the beginning of 1941. Can't be an Avro Manchester either, they only had two engines and first flew in 1939.
Factual error: When the Ranger trainees first meet Samuel L. Jackson, he's wearing the rank of a Specialist on his collars even though he's a Master Sergeant. Title 18, Chapter 33 of the US code prevents the unauthorized wear of a military uniform (among other things), however this does not automatically correct the mistake since a common misconception is that one slight alteration is sufficient to make the uniform legal. Having the wrong rank on is too obvious of an alteration, especially for anybody who has spent more than a day in or around the Army and would still be punishable by law, if he was dressed in an attempt to fool your average citizen outside of a movie.
Factual error: The 20 banknote shown is multicoloured, but the real one is plain blue. (00:40:40)
Factual error: At the end when they are loading Dewey into the ambulance on the stretcher, it is standard procedure to put the patient neck brace when they receive any type of unknown injuries (stab wounds) to their back as Dewey did - it was notably absent.
Factual error: When Bruce Willis is looking at his old high school news clippings you see a professional baseball score on one of the newspaper clippings. The game was Pittsburgh vs. Arizona Diamondbacks. The Diamondbacks were not a team yet when he was in high school. (00:33:35)
Factual error: Jodie Foster states that as a propulsion engineer, she knows the internal structure of the plane by heart and has worked extensively on it. The problem with that is that propulsion engineers work on the jet engines - which are all on the outside of the plane, on the wings. Sure, a propulsion engineer might have some basic knowledge of the plane's interior design and engineering, but the in-depth knowledge she claims comes from her job simply isn't right - that's the job of avionics engineers.
Factual error: Opening the blank envelope, Marta finds the fragment of the toxicology report. It is signed "Office of the chief medical examiner, Norfolk County, Massachusetts." But then it writes also the address of said office, which is in Marlborough. Marlborough is also the city when Marta resides, and where the lawyers' letters we see come from. But Marlborough is also a city in the Middlesex county, not Norfolk. (01:28:25)
Factual error: When Holland March is swimming behind the bar with mermaids, "Get Down On It" from Kool and The gang is playing. That song did not come out until 1981 and the film is set in 1977. (00:39:50)
Factual error: In the scene at the beginning of the movie as the 3 youths walk up the street, you can see current MA license plates, although the action should have taken place many years earlier. (00:01:30 - 00:05:50)
Factual error: When Harry is confronting the bank robber and the robber says he has to know if Harry had any shots left, Harry cocks the hammer which rotates the cylinder. If you watch closely when he pulls the trigger the cylinder rotates again. This can happen only when the trigger is pulled in double action mode (hammer down). (00:14:00)
Factual error: In the scene depicting life on Baker Street (after the "Sherlock Holmes" title), a horse-drawn carriage races through the streets of London. The only problem is, the carriage is driving on the right side of the road with others passing on the left. In England, carriages would be driving on the left. (00:07:05)
Factual error: A girl is playing with a Tamagotchi virtual pet in the scene set in 1994, but the toy was not released in Japan until 1996 (it wasn't officially available in the USA until May 1997).
Factual error: The geography around the VLA in New Mexico is actually relatively flat - in fact one of the reasons why the array complex is there is because the land is flat. The canyon in the film was actually Canyon de Chelly, in Arizona, more than 170 miles (270 km) away. But in the film, when Ellie goes to the canyon, the radio antennas seem to be right there, insinuating that the canyon is part of the VLA's magical desert scenery.
Factual error: Winter in Antarctica would not have a night and day as portrayed, with the amount of light changing so much during the course of 24 hours.
Factual error: When Shorty is removing Jennings' memories in the beginning, the pictures shown are from a third person viewpoint. If they are his memories, shouldn't these be from Jennings' viewpoint? (00:06:40)
Factual error: All the scenes which are supposed to play in Zürich were being shot in Prague, the capital of Czech Republic. The director didn't choose Zürich because the city was too clean for him. The signs on the walls are sometimes written in Czech language, and the people speak German with a strange (Czech) accent, not like someone from Zürich.
Factual error: The solar panels (or mirrors) are facing away from the sun. The sun's position can be estimated from ground shadows and object highlights and the panels are facing in completely the wrong direction. (01:11:40)
Factual error: During the custody hearing, the Maryland flag in the courtroom is upside down. The rule for a Maryland flag is "black and gold, top of the pole," this flag has the red symbol at the top.