Deliberate mistake: In the fight scene with the chariots Maximus takes one of the horses from a chariot and jumps on it. The horse already has a saddle complete with stirrups despite the fact it was pulling a chariot and not carrying a rider. (01:23:30)
Deliberate mistake: When Leonard snaps a picture of Jimmy's body his head is lying between his shoulders looking straight up, but in the polaroid his head is lying to the right, and it is, in fact, a different actor altogether. (01:39:10)
Deliberate mistake: Elizabeth Shue uses a drawer handle as an electromagnet. OK if it's really a magnetic material but lab furniture is generally made of aluminium or stainless steel which is not. There is no way that they would use an iron handle in a potentially wet, and hence corrosive, environment such as a freezer.
Deliberate mistake: When Reinaldo is narrating right after the police begin to crack down on the gay movement in Havana, he speaks of "sex as a weapon against the regimen". Shouldn't it be the regime? (00:44:20)
Deliberate mistake: When the limo driven by Gwen (Sandra Bullock) runs over the white picket fencing it's not Sandra's face behind the wheel in the exterior shots. Also, when Gwen runs over the short white picket fencing, in the interior shot from the car the corner of an 'L' shape fence is being hit, then in the front exterior shot the end of a smaller fence is hit. This is cut from a longer sequence, the smaller fencing is seen way in the distance in the first shot. (00:07:45)
Deliberate mistake: When Carlo and Bonehead go upstairs to confront Jack at the hotel, Bonehead accidentally shoots Carlo in the leg and Carlo fires eight shots in retaliation at Bonehead killing him. Carlo immediately bursts into Jack's room same gun drawn. When Jack jumps out the window Carlo begins firing and shoots another 15 times. There is no way the single clip in the gun Carlo uses could possibly fire 23 rounds.
Deliberate mistake: In the scene with all the coffins and new Skull "recruits", Lucas knocks on the unopened coffin and Caleb pops up. The next shot is a wider shot that shows everyone standing around Caleb's coffin, but the guy in the coffin is not the actor playing Caleb, but a stand-in.
Deliberate mistake: The Americans actually spoke with American accents, but these very new Americans were British in origin, and so they couldn't develop a new accent in such a short time. The Americans should still have British accents. This would have been confusing and is done for the viewer's benefit, but still a mistake.
Deliberate mistake: In the scene near the end of the movie when Trigger is in the bilge trying to stop the air leak, the concussion of an artillery shell fired from the destroyer shakes some pipes loose. The mistake is that one of the flanges visible on a section of pipe has no bolt holes, making it impossible to join that pipe to anything.