Revealing mistake: In the disco scene, the DJ is playing music, but the Pioneer decks and the DJ Mixer are not even turned on, as no lights are showing.
Revealing mistake: When Troy says "I'll sing with her," Ms. Darbus turns around "in response" to his voice before he even says anything.
Revealing mistake: During the scene at the restaurant in Montenegro (actually filmed in the Czech Republic) you see a payphone with a Czech Telecom logo on it (itself a piece of history as these are all now rebranded O2). (01:57:50)
Revealing mistake: When Eric Matthews is smashing his foot, he hits it the first time and it shows a close up. If you watch the small amount of blood when he hits it again they have used the same shot. (00:04:00)
Revealing mistake: When the Bronco is underwater at the end of the movie, Claire's hands are tied to the steering wheel. Doug rips the steering wheel off. Anyone who has worked on cars knows you need a puller to get a steering wheel off. Also, the steering wheel is gone when Claire swims to the surface.
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: When Alex sets-off the smoke bomb in the warehouse, the smoke is coming up from under the grate in the floor nowhere near the DS.
Revealing mistake: During the final conversation between Detective Frazier and Arthur Case, Frazier holds up his hand with the ring on his middle finger. It is pretty obvious that the hand was inserted into the scene in post production; the hand doesn't move in a natural way and simply looks out of place.
Revealing mistake: When Costello's men drive off, after throwing Queenan off the top of the building, the state troopers are firing at the van. One back window is shot out, then in the next shot of the van the other window is shot out and then the same one is shot again so the one window is shot out twice in the same scene.
Revealing mistake: Near the end, right before Nita goes after Kenai, she takes off her dress. If you look closely, when she takes it off, her necklace and earrings come off with the dress as if they were a part of the dress. Also, her hair is tied back when she's wearing the dress. But when she takes it off, her hair is loose and flowing.
Revealing mistake: When the children run along with the car waving, you can see a modern digi-watch on the wrists of one of the children, which was not produced during the 1970s.
Revealing mistake: Watch closely when the first two 'slaves' run for their freedom amidst flying spears. When Jaguar Paw's friend (the chunky fellow) gets speared, it is a 'through the armpit' effect. When he's gasping for breath in the next shot, the entry of the spear is actually more in the middle of his chest.
Revealing mistake: When Megan peeks through that slot thing at least two of the bad guys look straight at her.