Revealing mistake: The spy contact lenses that Owen Wilson and Eddie Murphy use were originally supposed to be for Carlos, but if you notice, the lens that Owen Wilson uses is blue to match his eye colour. Carlos has brown eyes.
Revealing mistake: When the people come to take the girls away, the mothers and girls run, with the camera in front of them. You can see the wheel tracks in the dirt from where it is being towed back.
Revealing mistake: After blue-Marty exits the pool he heads upstairs and when Jason and Kaylee spy on him dancing (with Mr. FB) Marty's entire body is dyed blue, but the blue only reaches to just above the bottom of his bare feet.
Revealing mistake: After Spirit gets his second wind when the Colonel is attempting to break him, he breaks the girth/cinch strap by catching it on the fence. At one brief point, the pole of the fence actually appears to pass between Spirit and the girth of the saddle.
Revealing mistake: When Steve and Terry first attempt to catch the rogue crocodile in the river, during several shots you can see that the river bank is concrete and fake rocks.
Revealing mistake: When the doctor intercoms the colonel because he cannot get into the medical room for the pregnant woman having nightmares, the camera shows the intercom, which is simply the back end of a desktop computer with a couple of knobs stuck on it. (00:24:50)
Revealing mistake: Hercules walks out at night and suddenly encounters Megara in the forest. Directly afterwards you see them walking off in the distance. The wall behind them has some torches on it, but apparently these were added in post production: One of them shines right through their bodies as they walk past. (00:47:00)