Factual error: Fitch, who professes qualifications in biology, genetics and biochemistry, says that they made Sil female because she's a natural predator and so she'd be more docile. He should retake his finals. In every single species of predator on earth - every single one - the females are the hunters, aggressors and killers. The males may be socially dominant but they are the 'docile' ones. There are no exceptions - and no human DNA was used to create Sil - they used synthetic DNA based on the instructions transmitted to them.
Factual error: No electricity, yet the washer is running.
Factual error: When Zach and Nomi are talking on stage after Nomi's disastrous experience at the boat convention, Zach places a call to Phil Newkirk. There are several problems with the call: the cell phone doesn't appear to be on (he raises the antenna at the beginning and end of the call, but he never presses an "on" or "off" button); Zach doesn't punch in enough numbers for the call to appear legitimate (too many numbers for speed dial, but too few for a local seven-digit phone number [also, since he was using a cell phone it's unlikely that he dialed a hotel extension number]); and the pauses between his words and Phil's response on the other end of the line are too short to be believable.
Factual error: When McClane and Zeus take the little hatchback from the bank location, they run up the ramp by the Brooklyn Bridge and McClane looks to see the dump trucks aren't on the bridge. Zeus then spots them on FDR Drive and they speed off down the ramp to FDR Drive. The ramp they were on doesn't connect to the ramp they took to give chase. It only heads towards City Hall or over the bridge. They'd have to take the Civic Center ramp, do a u-turn under the Brooklyn Bridge approach then head back up the ramp to FDR Drive.
Factual error: Throughout the movie, all sorts of messages are passed over the 1MC (ship's intercom) when the boat is supposed to be stealthy. They've set "Ultra Quiet" to avoid the enemy sub but no-one was any quieter, and everyone was still using the 1MC. Worse, people are shouting commands and status updates, both in person, and over the intercom! No wonder that Akula found them. The only thing protecting this ship was plot armor! In real life, messages would be passed quietly using sound powered phones (which we also see), rather than blasting the info loudly to the entire crew, because sonar will literally pick up the sounds of loudspeakers and people shouting. Let's not even mention classified target data being passed to the entire ship's crew on the 1MC. (00:49:00)
Factual error: If you take the train from Paris to Cannes you won't pass the Eiffel tower.
Factual error: The suits worn by dangerous disease researchers would definitely never tear if the hose was pulled.
Factual error: When Lovell's daughter is complaining that the Beatles have broken up, she slams the album Let It Be into her rack. The scene takes place on the day of the initial explosion aboard Apollo 13, April 13 1970 - immediately prior to the Lovell family attending the screening of a television broadcast from the spacecraft. Let It Be was not released as an album until May 9th, 1970. In April Ringo was still recording drum tracks, not even possible for an advance copy to get out.
Factual error: When the porter first gets ready to shoot at the terrorists (after Ryback falls off the train) he goes through a series of verbal instructions to remind himself what to do. The very first thing he says is "safety off". The problem is that the gun he is using is a Glock pistol. Glocks use a device called a "safe-action trigger" but they don't have a manual safety that you turn on and off.
Factual error: Near the end of the movie, as the money train is approaching the passenger train, the motorman is communicating on the microphone with dispatch. If you notice, as he is talking, his hand is NOT on the throttle. On the trains in the NYC subway system if the throttle is not depressed the train will stop.
Factual error: When it's 1969 we see a boy (I'm not sure which one so you'll have to look) riding a Shwinn Sting-Ray Krate Grey. That bike didn't come out until 1971 and they only made them that one year. (00:02:45)
Factual error: Various Sydney landmarks can be seen throughout the movie (although the Centrepoint Tower and the Monorail play major roles). There are also some cars that have right-hand steering wheels despite the story being set in California, and some Australian model traffic lights (foot-long black cover with a grey pole) can be seen when the Scorpion bot destroys a car in front of the rangers. (01:06:00)
Factual error: The roads show only two wheel tracks, there is no wear on the center of the road, from either horses or oxen. Most pre-auto movies miss this.
Factual error: Almost at the end of the film, Poncelet is marched to the death chamber, with Prejean's hand on his shoulder. They are led past an open door - which leads to the viewing room, where the witnesses will congregate. Some of them are already in the room. This is nonsense - it is inviting a bereaved relative to attack the condemned man. In fact the corridor to the death chamber goes nowhere near the witnesses' area, and Prejean would have had to have been escorted back through two guarded doors to reach it.