Revealing mistake: While Indy and Marion are in the Well of Souls, and they encounter the snakes, Indy falls to the ground only to be confronted by a hissing Cobra rearing its head. Look carefully and you'll see the snake's reflection on the safety glass between it and Indy. Briefly you can also see the torch's reflection while he's waving it around. You can also see Marion's reflection when she falls in later on and is face to face with the cobra. [This has been corrected in the new DVD set. You can only see it if you have the original VHS. I think it's visible in the "making of" on the DVD as well.]
Revealing mistake: When Loomis shoots the marshal's window out, when he makes a u-turn you can see the tire marks on the road and dirt from previous takes.
Revealing mistake: At the beginning when the ruler is making his speech, you can see his modern day fillings in his upper molars.
Revealing mistake: When Bond throws the dead pilot out of the helicopter, you can tell it's a dummy as its arms and legs bend at impossible angles.
Revealing mistake: At the end of the film when Ginny and Paul are fighting Jason, his machete hits the shrine where his mother's head is displayed and where Terri's body is strewn. When the machete hits, Terri flinches, even though she is dead. (01:16:00)
Revealing mistake: 'Nightwind', the film at the centre of the drama, has finished shooting, and has been edited and postproduced, has premiered and bombed. All of this would take months - for a major production, up to a year. So why are the sets still standing on the studio sound stages?
Revealing mistake: When Ash shoots Cheryl through the door in the head, you can clearly see the hose (not an artery) that's squirting out the blood. (01:16:14)
Revealing mistake: In one scene just before the attack on a big Hunter the young captain (Jürgen Prochnow) is sitting with his charts. Beside him he has got a glass of beer standing. The sub lurches heavily right and left in the hard weather, but the surface of the liquid stays the same.
Revealing mistake: When Wally is firing the laser at random from the small spaceship, we see Fidget running down some stone stairs, and there are violent laser impacts directly behind him that could only have hit where they did if they had passed right though his body. (01:41:55)
Revealing mistake: When the tanker crashes at the end the driver is clearly wearing a crash helmet.
Revealing mistake: When Bill Murray is blowing up the prison door, you see the explosion, but the explosive is still intact.
Revealing mistake: During the Inquisition song when Right Before Mel Brooks Plays bongos on the guys heads he slides in from behind the wooden torture things. If you look closely the hair on the stunt double sliding in is darker than Mel's.
Revealing mistake: When the father moves to close his dead daughter's eyes, the daughter's eyes close before the fathers fingers close them.
Revealing mistake: When Norman and Billy crash the boat, the side panel rips off of it before they hit the rock.
Revealing mistake: When Foyt wants to put the GMC van into neutral at the police roadblock, you can see the cable towing the van towards the police car. (01:03:30)
Revealing mistake: At the end when Snake drives over the hidden land mine and the cab is blown in half you can see three sets of wheels under the front half of the cab and a strange looking flap probably used to conceal them. (01:24:50)
Revealing mistake: When the skull the children leave at the caretaker's hut falls over and engulfs him in flames you can see the stuntman's protective head gear.
Revealing mistake: When the mounties are attacking Johnson's cabin, one of the men with them crawls into a bear trap. You can plainly see that the jaws of the trap are made of rubber or some other soft material when he struggles.
Revealing mistake: When Betty and Oliver go to the coffee stand, immediately after Betty says "Plus one," you can see that the guy working the stand just grabs two cups from his stand without pouring coffee into them and gives it to Betty and Oliver, who drink from the empty cups.
Revealing mistake: When Joe has died of blood poisoning there is a close up of his head and neck, you can see him breathing and his eyes flicker.