Revealing mistake: In the final scene where Fonda and Holbrook are looking over the carrier at the crowds on the dock you can see that only the first rows of people are dressed in period clothes, the rest of the crowd are dressed as they would have been in 1976 when the film was made.
Revealing mistake: Near the end when Ace gets into his Cadillac, in the first shot facing the front of the car, there is a protective glass in front of Ace (the same width as the windshield) with the dashboard in between that glass and the windshield. Note the vertical edge of the glass is visible at the right side, and the rearview mirror's sticker on the windshield casts a shadow onto the second glass. During the stunt, the flames on the dashboard are between the glass shield and the windshield, keeping the actor safe from harm. (02:46:05)
Revealing mistake: When Mr Witt rides out of the Zulu camp in a 2 horse cart at the beginning of the movie, just before it exits, you can see it's a stunt double at the reins.
Revealing mistake: When the 54th Mass. marches past a liberated plantation some black children wave them on. One of them is wearing a digital wristwatch.
Revealing mistake: When the spear handle is protruding from Hector's shoulder, the area of the armor around the circular wound is clearly visible and it is in perfect condition. There is no tear in the armor whatsoever, around the wood, which would have been necessary to allow the wide spear tip to penetrate the armor and actually enter Hector's body as it did. (02:01:20)
Revealing mistake: Midway through the movie, there is a long-shot of several characters walking outside between two gutted factory buildings. The camera pulls back, zeros in on the base of a huge chimney and pans upward to the very top - where two men in black and white checkerboard jackets are working.
Revealing mistake: In one of Pickett's charge scene the bayonets are obviously rubber.
Revealing mistake: Just after Li Mu Bai tells Shu Lien that they are very close to her headquarters and that she should check in, we are treated to two 'time pass' shots of forest. The second of these features some very obvious power or telephone lines in the lower right corner of the screen. (01:22:40)
Revealing mistake: When the Muslim emissary arrives to Jerusalem and Guy de Lusignan stabs him under the chin, look at the blood. It bursts from something attached to his shoulder. In addition, the emissary is seen as stabbed with a small dagger but then Guy De Lusignan is shown holding a full length blood tipped sword a second later.
Revealing mistake: In the first major battle between the 300 Spartans and the Persians, Leonidas is slaughtering the Persians and the speed of the scene goes from slow motion to fast motion, you see very realistic CGI blood. When the blood hits the the ground it suddenly disappears. This happens many times during this long and awesome scene.
Revealing mistake: Just before the Roman soldiers pressed Simon of Cyrene to help Jesus carry the cross, Jesus has fallen and we see that the bruised and swollen-shut eye is now his left. The shot changes and when it comes back to Jesus his right eye is swollen shut again. The film must have been flipped.
Revealing mistake: At the end of the movie, where Sgt. Eversman talks to the dead Corporal Jamie Smith about Blackburn, he says he's gonna talk to Smith's parents when he gets home. When Eversman places his hand on the chest of Smith, you can see his eyelids move. (02:14:08)
Revealing mistake: In the scene after the battle of Agincort, where Henry and his retainers are walking meditatively among the heaps of the fallen, if you look carefully, you will see one of the fallen with his head raised watching the procession. He then realizes that he is on camera and puts his head back down. It's near the edge of the screen so may occasionally be cropped.
Revealing mistake: The cannons shown are firing blank charges, which produce no recoil. Recoil has been simulated by towing the guns backwards when they fire. The problem is, there is always a distinct delay between the discharge and the "recoil." The cannon also seem to largely fire explosive shells. At no point do we actually see a cannon ball rolling or bouncing along the ground or into any group of soldiers.
Revealing mistake: Towards the end of the film, when Hilts (Steve McQueen) is in a motorcycle chase with the German guards, if you watch closely, when the camera cuts away from Hilts and to the German motorcyclists, you might be able to notice that one of the guards chasing McQueen IS actually McQueen! They used him to play one (or maybe more) of the guards because of the experience he had with motorcycles. This can also be seen in some behind the scenes footage on the DVD version of the film.