Factual error: In the balloon scene, it seems like Q can circle around and land on a spot where he flew past previously. A balloon can only fly in the direction of the wind.
Factual error: When we first see Fatima Blush, she is waterskiing. She is doing several stunts, which are only possible with one ski, the most notable being skiing backwards with one foot in the air. However, when she releases the tow rope and skis up the ramp into James Bond's arms, she is on two skis. (00:45:55)
Factual error: Cochrane chases Murphy in a Hughes 500 which has a top speed of 147 mph and easily keeps up with him, demonstrating that Blue Thunder's top speed is less than 150 mph. The F-16s sent after Blue Thunder have a stall speed of 175 mph. They would have to slow down to the point of falling out of the sky to have a shot at Murphy. Its utterly impractical and far more likely that the military would have sent AH-1 Cobra attack helicopters after him.
Suggested correction: Not necessarily. The F16 (and other fast movers) can and do engage slow moving helos all the time. They just engage them by missile from a long distance, where speeds are irrelevant.
I'm no expert, but I wouldn't think the US Military keeps helicopter crews on Alert Status like they do for fighters. This film was during the Cold War, so maybe, but it wouldn't make sense to keep an attack helicopter crew (and ground crew) on Alert like they would for fighter jets. Even after 9/11, I wouldn't think a (armed) helicopter crew would be beneficial to keep.
Factual error: The caption says "twenty years later" before the main part of the movie starts. Now judging by the dates we've seen on-screen so far that would be in the reign of William and Mary, not Queen Anne.
Factual error: The supercomputer has the British spelling 'Defence' written on it, instead of the American 'Defense', even though the movie takes place in the USA.
Factual error: Star shuriken, despite common misconception, are not inherently deadly weapons. They were mostly used for distraction, since their lack of a single weighted point makes their attack rather inefficient (although the weapon could be coated with poison). Although it is possible to hit an eye, it is very difficult to hit such a small target or scoring a sufficiently deep wound to penetrate to the brain with a star shuriken.
Factual error: In the final gun battle at the end of the film, Harry shoots the last bad guy so he falls off a high spot on the roller coaster and through the roof, into the carousel building. Yet as the credits roll, there is an aerial shot and you can see the carousel building at the left of the screen, with no hole in the roof. Also, the carousel building and the roller coaster are about 200 yards apart.
Factual error: When the coroners are taking Betty Johnson's corpse on a stretcher, her head is uncovered. They cover the heads of corpses. The head is only uncovered if the patient is alive. (00:12:35)