Factual error: During the scene inside the submarine, you see a Commander (O5) giving orders to a captain (O6). This would never be a thing on any vessel. You would have a Commander as a Commanding Officer on a submarine, but not having a Captain working for the Commander.
Factual error: At the Western Front camp near Washington, you can see tanks moving with their cannons raised to the highest angle. In reality, tanks move with their cannons in a horizontal position. The cannon is raised only when it needs to hit a high target, such as a high floor of a building.
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: When Axel first drives from the airport (while on the phone) towards Beverly Hills, he is coming from the wrong direction. He is shown on the interchange from the 105 Freeway westbound to the northbound 110 Freeway heading towards Downtown LA. If coming from the airport to that same intersection, he would be on the 105 eastbound into the 110 - not westbound.
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: When Santa delivers Christmas presents, he visits Rio de Janeiro, Paris, Sydney, and Tokyo in that order. Due to time zones, the correct order would be Sydney, Tokyo, Paris, and Rio. (01:53:00)