Factual error: This movie is set in 1935. Back then, executions were done by hanging. The Louisiana Legislature changed the method from hanging to electrocution in 1940.
Factual error: The old percussion double barrel shotgun is firing modern shotgun shells, which would never work or fit in that gun, and furthermore are also made of plastic, wrong for the era.
Factual error: The 20 banknote shown is multicoloured, but the real one is plain blue. (00:40:40)
Factual error: No airport in NYC has the view of the New York City skyline that Kevin has when he realizes that his family is in Florida and he's in New York.
Factual error: Worms are not created in AutoCAD. Ever. Period. Does not happen, cannot happen. Building design work and the like is done in AutoCAD. Viruses and worms are coded out by hand or created with a generator by slackers that don't know the code and then compiled into executables.
Factual error: During the first tunnel sequence, all the cars travel very far into the mountains, turn lots of corners, yet not only is Gisele still able to speak to them over the radios, their GPS still works. GPS signals invariably need a clear 'sight' of the sky and can penetrate light cover, but most certainly not that depth and cover. (00:58:05)
Factual error: In the movie, when the baby is born and Big Momma delivers it, the baby comes out without any blood and there's no umbilical cord. (00:34:20)
Factual error: In a scene set in 1862 or 1863 Bill the Butcher says: 'An Irishman will do for a nickel what a ****** will do for a dime or a white man for a quarter'. The first nickel 5 cent piece was coined in 1866. At the time of the scene the 5 cent coin was a small silver coin called a half-dime. (01:10:00)
Factual error: In the scene where Roxie is placed in the "paddy wagon" to be taken to Cook County Jail, the prosecutor refers to himself as District Attorney Harrison. However, the court system in Illinois doesn't have district attorneys; rather, they have state's attorneys. The original play by Maureen Watkins correctly calls him a state's attorney.
Factual error: We are told at some point that Nicole Kidman has dual nationality because she was born in the US. In the final scene, when she is talking with Sean Penn about her future steps, she says she has been deported and given one day to leave the country. She was a US citizen, so it is impossible that she would be "deported".
Factual error: When Yuri is narrating about selling weapons for the US government (this was around the scene when he sells M-16's by the kilo), he mentions Lieutenant Colonel Southern. However, when you see the him, he has Colonel rank, which is a silver eagle. The Lieutenant Colonel rank is a silver leaf, not an eagle.
Factual error: Helicopter rotor blades do not unfold by themselves and there is no way to unfold them from inside the helicopter. A trained mechanic with the right tools and equipment (including the proper ladder for the job) will take a minimum of twenty minutes to rig a four bladed rotor, and that's if (s)he's in a hurry. An airborne (i.e. falling) helicopter? Forget it. (00:07:40)
Factual error: In the scene at the beginning of the movie as the 3 youths walk up the street, you can see current MA license plates, although the action should have taken place many years earlier. (00:01:30 - 00:05:50)
Factual error: When Harry is confronting the bank robber and the robber says he has to know if Harry had any shots left, Harry cocks the hammer which rotates the cylinder. If you watch closely when he pulls the trigger the cylinder rotates again. This can happen only when the trigger is pulled in double action mode (hammer down). (00:14:00)