Factual error: The sisters run out of fuel for the helicopter, which is then shown slamming down on the ground and essentially destroying itself. All helicopters are capable of autorotating safely to the ground in the event the engine(s) quit. Of course, that would not have been as dramatic. (01:05:15)
Factual error: Let's go by the movie geography; our planet is a big matrioska. By diagrams shown, this Hollow Earth would be by the Earth's core, thousands of miles deep. They enter from a portal in Antarctica. And yet, Godzilla later in the movie burns a random hole in the ground in HK deep enough to reach it, roars through it and Kong hears it, and the ape easily climbs it to poke back to the surface. Even admitting you can do the magic "1,000 miles in 2 seconds" warp anywhere, the scale is ludicrous.
Factual error: Druig leads several warriors outside Tenochtitlan as it was sacked by the Spanish conquistadores, and they live peacefully in the nearby forest, for 500 years. The forest is of course the virgin Amazon forest, as captions say. Small problem; Tenochtitlan was in Central Mexico.
Factual error: It is not possible to have a conjoined twin of the opposite sex. They are similar to identical twins, which are always of the same sex, in that they are formed from a single zygote. In the case of conjoined twins, the zygote fails to divide normally.
Factual error: Lt. Harp is told by Capt. Leo that the Lieutenant has 56,000h of UAV flying time, That is ridiculous. Even seasoned pilots of the Military Airlift Command do not have that many hours. Drone pilots can fly up to 1,800 hours a year, and Harp hasn't been flying drones for 31 years straight.
Factual error: In the nighttime hostage rescue scene, the rescue helicopter has its right and green navigation lights on, which are designed to show other aircraft where it is and which direction it is heading. This of course would not be the case while staging a clandestine operation in hostile territory.
Factual error: Dwayne Johnson is pursuing a thief. He gets into a Porsche Cayman and pushed the start button, and he can drive off. But you have to have the key fob in your pocket or bag. Porsche explains: "As long as your key is close when you grab the door handle, the system automatically checks the encrypted access code on the key. Once your code is validated, the door will unlock, and you'll be granted access to your vehicle." Dwayne had no fob, as the car was just parked.
Factual error: Although it's a commonly used movie trope, cutting the brake lines on a bus would not produce the effect seen in the movie. Buses use air brakes, which by design, can operate even with substantial loss of pressure and often engage automatically if there is too much pressure loss.
Factual error: There is a "Covered California" sign in a window. The referenced health insurance exchange did not exist during the 1990 time setting of the movie. (00:20:58)
Factual error: In the opening race scenes, the cars on the track are out of date for 1989. The race car used by the aggressive driver (#23) who causes the fiery accident that kills Toretto senior is based upon a later model 1997-2002 Pontiac Grand Prix. The race car that Toretto senior is driving is based on a 1995-1999 Chevy Monte Carlo. (00:01:00 - 00:04:00)