Revealing mistake: At the end of the decisive game, the bad guy hits a deep foul ball. During that hit, they show the ball against a black background. If you look very closely at the bottom of the screen, you can see a hand throwing the ball.
Revealing mistake: The 'bear trap' clearly has no spikes in it, so how could it have wounded Nathan. This is ever so clear when Tori prises the bear trap open to get his leg out, and it snaps back. (00:52:00)
Revealing mistake: Near the beginning of the film, an axe is thrown at a priest. The axe should rotate as it travels, because the head is heavier than the handle. But it hangs upright as if drawn by a wire.
Revealing mistake: When Phil drives the truck off the cliff, you can see right through the grill of the truck (meaning there is no radiator or engine), and the transmission is also missing, as you can see when the truck is falling upside down. Without an engine or transmission it would be hard to drive off a cliff.
Revealing mistake: When the man shoots a target next to Jack's second cousin's head you can see a shot of him pointing his gun. It is clear there is a pole supporting the gun. (00:20:35)
Revealing mistake: When Jacquouille takes the jewels from the dead man, his hands move.
Revealing mistake: After the old lady steals the meteor rock from Luigi, the big lady in red picks her up and throws her off down below into a moving car. She gets up and shocks the driver, causing the car to rear end the vehicle in front of it. If you watch closely, you see the engine top shift forward and the back of it lifts up. This reveals it is just a fake prop attached to the vehicle and not a real engine.
Revealing mistake: Right before the witches burst through the roof of Max's house, after they retrieve the book, you can see the charge used to set off the explosion in the window just below where they exit.
Revealing mistake: The stick used to make Jack's dog levitate is sometimes visible, for example when Jack is alone on the mountain.
Revealing mistake: When they first arrive at camp and Joel goes to use his inhalers, the mouthpiece is actually in the storage position rather than the actuation position. The puff sound must have been added in later because the inhaler cannot be activated when it is put together that way. (00:22:20)
Revealing mistake: Walker meets his demise in sequence with a shockingly poor visual effect; he falls into the ocean from the cliff, and instead of splashing into the water, he sorta disappears quickly through it. (01:22:55)