Revealing mistake: When Michael Douglas attempts to swing on a vine over a deep abyss, the rock that he runs into on the other side moves like a marshmallow, indicating that it's a fake rock. (00:39:10)
Revealing mistake: When the TVs explode, the glass is very fake and "cardboardy".
Revealing mistake: When Harkin Banks almost loses control and skis through the lodge, the jump ramp is visible as the woman opens the door. (01:29:45)
Revealing mistake: When the guy on the horse pulls out his sword, he has trouble getting it out of the sheath at first and it bends severely. It is clear that it is not a real sword.
Revealing mistake: When Carolyn and the Geek are in the parking lot across from her church, Carolyn gets some help as she climbs over the side and out of the Rolls-Royce - as opposed to using the door. As she makes her way over the side, you can see that she steps onto a step-stool or similar above-ground block before stepping down once more with her next step onto the pavement. There is no such step on the car itself.
Revealing mistake: When Chocolate Mousse throws the anchor with the rope attached into the air, if you watch the ground when they run away, you can see that there's suddenly a lot more rope there, revealing that it was filmed in two takes and the anchor wasn't really thrown directly above their heads. (01:11:20)
Revealing mistake: Going to his father's old place, David and Allison turn right on the corner, pass some stores and then turn left to drive into the lot of the Texaco station. The reflection shown in the stores' windows across the street is not at all what is supposedly across from those stores. Also, when they start to pull away from the station a set of studio lights are reflected in the side back window of the car. (01:02:40)
Revealing mistake: When Roger is in the bathroom at the urinal, he can see Edwina's reflection in the mirror (as she is, supposedly, inhabiting his body). However, when Roger lets out a particularly big exhale, Edwina's bangs blow slightly upwards, showing that the "mirror" effect is achieved by simply having her stand behind a wall right in front of him. (00:29:45)
Revealing mistake: In the scene when Turbo is sweeping in front of the grocery store, he begins dancing with a broom and you can see the wires that are holding the broom up, making it seem like the broom is floating.
Revealing mistake: When the Hotel manager walks in the recently vacated room, we see the piano collapse. If you look closely, you can tell that the front two legs were just pulled back under the piano causing it to collapse.
Revealing mistake: When Ariel is playing chicken with the oncoming truck, as she is standing on both cars, notice that her hair is dark brown to black in colour, then it's blonde again. The hair colour changes a few times. It's obviously a stunt woman.
Revealing mistake: The seen where Teddy is standing in rain talking to Charlotte in her car you can see how the rain followed his movement. There is a thicker spout of water dripping and you can see the outline of it.
Revealing mistake: At the beginning when the one monkey falls to its death, it's obviously a stuffed animal posed as a dead monkey.