Factual error: Near the end of the film Knox is flying a Huey helicopter and the Angels hitch a ride by shooting it with a spear gun and dangling on the line behind it. Suddenly adding about 200kgs to a Huey in flight like that is going to cause all sorts of problems with the trim and airspeed of the aircraft - the pilot would know immediately that something was wrong. (01:23:20)
Factual error: The criminologist describes the events of the movie as taking place "on a late November evening". In the very next scene, Brad and Janet are driving in Brad's car, and President Richard Nixon's resignation speech is playing on the radio. Nixon resigned in August of 1974. (00:12:00)
Factual error: While Bridger is watching the film of the Mafia boss following Beckerman he signals for the film to be stopped so he can look at the close up shot of the man. He is watching a 16mm film shown through a bog standard projector - stop a film like that for more than two seconds without closing down the projector shutter (this doesn't happen - if it did the screen would darken instantly) and it will melt and catch fire. This doesn't happen.
Factual error: It is not possible to be "allergic to all known anaesthetics". Amongst the amide local anesthetics lidocaine, prilocaine, bupivicaine, mepivacaine and dibucaine are naturally occurring substances and if administered without a preservative they cannot trigger an allergic reaction. If Bales is allergic to them, he'd be allergic to the metabolic processes of his own body. They are all powerful local anaesthetics and could easily be used for a radical rhinoplasty such as that required by Bales.
Factual error: At the very end of the film Bruce is reporting on a drive for blood donors, and Grace leads him over to the booth to give blood himself - he is even wearing a tourniquet. However, he is supporting himself on a walking stick - he is not fully recovered from the injuries he received when he was run over, which happened when he was hit by a moving car - injuries which left him clinically dead. There is absolutely no way that a person who has suffered life threatening injuries and has undergone the (inevitably) intensive drug therapies and surgical procedures involved while under treatment in hospital in the fairly recent past would be allowed to give blood. There is no way that the Red Cross (or the US equivalent) would want to encourage people who have recently been hospitalised to try to give blood. Not only would that be the height of irresponsibility, they would be wasting precious resources and staff time turning away people who would not be allowed to give blood.
Factual error: When Amy is fired from S'Nuff magazine she takes her story on Aaron Connors to Vanity Fair, who run with it. That is not going to happen. Amy wrote the article while a paid employee of S'Nuff magazine and that means the copyright in the article (and, very relevant to this issue, the photographs of Aaron they paid to have taken), resides with them, not with her. It isn't hers to sell. No magazine editor of any standing is going to buy an unsolicited article without checking its provenance backwards and forwards, and that would mean checking with Amy's previous employers - after all, what would happen if they changed their minds and ran the story themselves?
Factual error: Basic physics - Hancock throws Michel from a dead stop to above cloud level in about eleven seconds. The clouds are bog standard cumulus which form at around 7,000 metres in temperate zones. This means that Michel accelerates to about 700 metres per second instantly, from a dead stop. Obviously he cannot accelerate during his ascent, so his starting speed has to be at least that. (In fact he would have to start his ascent much, much faster than 700 metres per second as he would be constantly decelerating due to gravity and air resistance, but it will do as a start point.) Michel accelerates from 0 to 2,520 kilometres per hour - twice the speed of sound - in zero seconds. He would be accelerating at around 5000 Gs, turning him into a very long streak of fine, pink mist.
Factual error: Then, as now, every recruit reporting to boot camp would be tested for illegal drugs, first by a urine test and then by a broad spectrum blood test in the case of a positive result. There is no reason for Elmo to try to hide his stash when the recruits are told they are to be tested - he is going to come up positive anyway. He may as well just say he has changed his mind and walk away. He is entitled to do that any time up to ten days after he signed on, and it happened a lot in real life!