Factual error: When Rain shoots the Xenomorphs in zero gravity, their blood forms long ribbons and other splatter-type patterns. In reality, due to surface tension, liquid in zero gravity forms into spheres. The blood would not have remained 'stretched out' like it does.
Factual error: The Torre delle Milizie is visible from the courtyard in the Vatican and looks fairly close. You can't even see the tower from the Vatican. It's quite a long way away.
Factual error: Whilst trapped in the basement, the two sisters pull a rug towards them to obtain some matches, then take them downstairs and light them by striking them on a rough surface. The matchbox is labelled 'safety matches' so they would not light without using the striker pad on the box. (01:12:00 - 01:14:00)
Factual error: The characters are using Channel 9 on the CB radios, which is a reserved channel for emergency use, not civilian use for communications.
Factual error: The physicist is on a quest for magnesium oxide, but it's one of the easiest things to obtain; magnesium is used in some engines, alloy wheels, and the humble block of magnesium used in camping fire starters. One could simply cut a ribbon of it, set it alight, and voila! Magnesium oxide.
Factual error: The movie is set in the US, but there are several things which aren't found in the US that give away the fact that it was shot in the UK. In one scene, a Tesco superstore can be seen in the background and the lift bridge seen in the film is Kings Ferry Bridge which connects the Isle of Sheppey to the Kent mainland.
Factual error: Justin Kemp is summoned for the jury hearing on Monday, 26 October 2022, according to the letter his wife holds in close-up at the beginning of the movie. Hard to be there on Monday, since 26 October in 2022 was a Wednesday.
Factual error: The insignia on Staff Sgt. Branson's uniform is incorrect. The insignia on her camouflage blouse is for a US Army Staff Sgt, not a US Air Force Staff Sgt. (00:03:58)
Factual error: Near the end of the film, each time Harker pulls the trigger to shoot, the magazine doesn't spin to load a new bullet. This is especially noticeable when she tries to shoot the doll.
Factual error: The President and Agent Miles commandeer a small plane at an Astovian airfield to fly to Ramstein U.S. Air Force Base. Miles identifies the craft as Air Force One, as the President is on board. However, "Air Force One" is the designation only for Air Force planes that fly the President (similar to how "Marine One" is called that because it is a Marine helicopter). Non-military planes, such as the one they are flying, typically carry the call sign "Executive One" when the President is on board.