Revealing mistake: When they are learning how to throw knives, the guy gets one thrown through his hand. If you watch this carefully, blood starts coming out of his hand before the knife hits. (00:28:45)
Revealing mistake: When the Pterodactyl is flying around with the egg, its shadow isn't cast as she flies over the trees.
Revealing mistake: When Spitz is stabbed with the pitchfork, you can see the line where the fake chest is. It's a different color.
Revealing mistake: During the "grand finale" fight scene, which takes place on the underside of an overturned helicopter hanging from a cliff, a few frames show the rigging that is holding the helicopter in place.
Revealing mistake: The final scene is filmed in Brant Rock MA, and the weather is blatantly CGI. If you notice almost everyone is bone dry in a supposed driving rain storm. Look especially at the character perched on top of the submarine tower. For contrast note the "pizza delivery" scene where it is raining heavily and everyone involved is soaking wet.
Revealing mistake: Just after Madison says to the Angels, "Looks like one of the three amigos has gone adios" and Drew gets thrown by Madison, Drew hits the wall. For some reason, the camera vibrates.
Revealing mistake: When the Enterprise is leaving space dock, look at the right (starboard) side of the ship. You can see the shape of the mounting arm the model was mounted on, even though it was blacked out to look like space, and it also blocked out the bottom of the dock. The footage was reused from Star Trek: The Motion Picture.
Revealing mistake: When the Hulk walks through the stream, the water doesn't react to his feet. (00:59:20)
Revealing mistake: Look closely at the footage when the vampires are entering the cave. Later when they are exiting the cave, the waves are flowing backwards. The same footage has been reversed. (01:17:05)
Revealing mistake: In the scene where Ronnie visits Brundlefly for the second time we see Brundlefly walking on the ceiling and wall, however his shirt doesn't remain consistent with gravity. This is especially obvious when he pulls his shirt up to show Ronnie his new tumor and then places it back down. The shirt appears to be being pulled up to towards the sky from Ronnie's perspective. (01:07:30)
Revealing mistake: When Wick is rubbing his toeless feet, the shot changes so that the camera is behind him and you can see him still rubbing except now you can see that he is simply curling his toes over.
Revealing mistake: In one scene, the Penguin is making a "bat" shadow puppet on the ceiling. But there's no light behind his hands. If there's no light, there's no shadow. (01:03:45)
Revealing mistake: In the beginning scene on the Bak'u planet the stone bridge bends under the weight of the child. (00:04:15)