Factual error: When asked how many seas the water from the Triton light is from, Huard says eight and is corrected with an answer of seven. The real number is 22.
Factual error: A cordless nailgun takes about 2 seconds to recharge and cannot fire consecutive nails nearly as fast as depicted.
Factual error: When Izzy urges Tom to watch through the telescope on the rooftop, he just looks and sees the nebula. From space observations done by myself, I know that the earth rotation is so fast that even for this amount of time, a manual correction must be done to center the view again.
Factual error: In the scene where Eric and Chrissie are by the pool, the song "All Right Now" by Free begins to play in the background. The movie is set in July 1969, and this song wasn't released until mid-1970.
Factual error: When Smithers (not identified by name in the movie) gives Alex his kit, it includes a fountain pen which shoots a dart filled with Sodium Pentathal. That's supposed to cause a person to do what Alex says. Sodium Pentathal is a form of barbiturate. Barbiturates cause impaired coordination, therefore it's unlikely that Mr. Grin could have flown a helicopter under its effects.
Factual error: In an early runway scene, a billboard for the film Chicken Little (2005) can be seen in the background.
Factual error: When American Cosair fighter planes strafe the Japanese soldiers with their machine guns, only two columns of bullets are seen striking the ground. These planes had six machine guns; there should be six columns.
Factual error: When the crowd is gathered outside of the Armstrong homes, there is an extra wearing a "G-Unit" shirt. The movie was set in 1999, but G-Unit didn't launch their clothing line until 2003.
Factual error: The movie apparently takes place in a Boston suburb, judging from the Massachusetts license plates, but, in the scene in the train station, the words "Long Island Railroad" are on a sign.
Factual error: Cindy and Brenda watches the news camera footage of Detroit before and after the tripod attack. But the city shown is actually San Diego. (00:40:45)
Factual error: The kind of CCD bar code scanners used by the cashiers in the movie have a maximum read range of just a few inches (or less). Given this limitation, it would be impossible for Vince to scan the item from as far away as he did, at the beginning of the movie.
Factual error: The helicopter believed to be carrying Howard Hughes is a Eurocopter AS-350, a design that had its first flight in 1974, three years after the events of this film. (00:02:00 - 01:18:40)
Factual error: When Chris is running from the cabbie he jumps into a train, and in the process gets his scanner stuck in the door, which he loses hold of as the train begins to move. BART trains will not move unless all doors are secure, so this could not have happened. (00:30:00)
Factual error: When the family is beginning their trip, Bob has difficulty putting the RV in gear. We hear gears grinding despite the fact that the vehicle obviously has an automatic transmission (as evidenced by the column shifter). Automatic transmissions do not contain the same type of gearbox as manual transmissions, and it is impossible for an automatic to create a gear-grinding noise. (00:13:30)
Factual error: About 11 minutes into the film, Luthor's yacht is seen in heavy seas in the Arctic. The helo on the helo deck has its rotor blades extended. This would cause immediate damage to them so is never done, even on carriers - the helicopter wouldn't be able to fly properly. (00:11:20)
Factual error: When Josh Hartnett's character pulls up the bathroom tile and find the cash, the bills are labeled "Federal Reserve Notes." Federal Reserve Notes didn't come into use until the 1960s. Back at the time of the Black Dahlia murder, Silver Certificates were in use.
Factual error: In a bleak snowy cityscape that depicts New York City in the late 1970's, there is a small satellite dish attached to a rooftop. It is the kind that DirectTV and the Dish network employ today, but probably not at the time period in question.
Factual error: When the boys go for their Oxbridge interviews, the weather is beautiful, very sunny and warm, summer. However, all Oxbridge interviews take place in early December.
Factual error: Midway through the film, the IRA flying column successfully ambushes a motorised British patrol. Immediately afterwards, when the column's survivors are milling about on the roadway, one IRA man is shown to be armed with a German Mauser Kar 98k bolt action rifle. This is historically incorrect, as this weapon did not go into production until after Hitler's assumption of power in the 1930's - at least thirteen years after the events depicted in the film.
Factual error: When Calvin is examined by the doctor, the doctor notes that he has a large scar on one side, possibly as a result of an appendectomy. The scar is 1) very sloppy; 2) pointing the wrong direction; and 3) on the wrong side of the abdomen for an appendectomy scar.