Revealing mistake: When the cook's body is lowered to the kitchen floor, you can see her move her outstretched arm closer to her head.
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 the taxi goes over the edge to capture Dr. Neville, you can see that the underbody of the car as it goes over is a flat painted surface and not the underside of what should be there (i.e., muffler, gas tank, etc.).
Revealing mistake: After the heroes get snared and surrounded by Ewoks on Endor, the Ewoks mistake C3PO for a god and start bowing. There is one Ewok which only has holes where the eyes and mouth are and you can see the eyes and mouth of the person inside the Ewok costume. (01:07:50)
Revealing mistake: When the chair moves across the kitchen floor, Craig T. Nelson goes to investigate it (after it has stopped moving). He goes up to the chair and flips it over. If you look closely, Craig almost hits the camera with the chair's legs. You can tell this has happened because the camera moves up very quickly and Craig looks straight at the camera crew with very big guilty eyes. This is more easily visible on the widescreen version of the film. (00:33:30)
Revealing mistake: In the final shootout scene, when Rambo takes over the truck mounted machine gun, he shoots the driver, whose blood splatters a lot over the metal guards on the gun. If the blood splattered that much on the guards, it should be all over the interior of the truck which is revealed to only have blood on the floor - none all over the dash or doors.
Revealing mistake: When Hans discovers the first bad guy lying dead in the lift ("Now I have a gun - HO HO HO!") and pushes his head, the corpse is moving his head before he is hit (watch carefully). He also closes his eyes before Hans makes contact. (00:39:15)
Revealing mistake: When Two Face and Riddler enter Wayne Manor, and knock Alfred down. Alfred, unconscious, pushes the dinner tray aside, so the thugs can carry him into the closet. (01:27:55)
Revealing mistake: Even though the story is set in Haddonfield IL, all of the cars have California license plates.
Revealing mistake: When Nancy is running up the stairs in her house to escape Freddy for the first time her foot hits the steps and go through the steps into some goop. Look at the steps above that step and you can see the pre-cut holes where the next sets of goop will be. (00:39:10)
Revealing mistake: In the swimming pool scene between Annette and Sebastian, a positioning mark can be seen quite clearly on the floor. [The swimming pool used was freezing cold, about 40 degrees, so Ryan Phillippe and Reese Witherspoon were freezing (look close and you can see Ryan shivering), and so were the camera crew, that they didn't repeat the shot, so the positioning mark was left in.] (00:28:05)
Revealing mistake: After Dr. Lawrence cuts off his leg and is crawling towards the gun, if you look at his dismembered leg, you can make out the shape of his foot hidden beneath his ripped up slacks.
Revealing mistake: When Inspector Lee was running through the casino, his hands are bound together with tape. When he tumbles across a gambling table, his hands come apart. When he completes the tumble, he quickly puts his hands together again. (01:09:00 - 01:10:15)
Revealing mistake: When the Hudson Ferry captain casts off the large label that reads "Hudson Ferry" is on his left side of his jacket. However, in the exterior shot as he looks out the window at the whirlpool, the label is on his right side. This shot was flipped, and amusingly, the CGI guys actually retouched the words "Hudson Ferry" so it wouldn't read backwards. (01:02:25)