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: 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: 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: 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: 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 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 the two station reporters are investigating Eddie's room, as the female bends down to the table, she is scared by a dog. In one shot you can see a black wire on the dog. (00:14:55)
Revealing mistake: Burke kills Mary Roberts. She blinks when he turns her head to check out her face. (00:47:10)
Revealing mistake: During the fight between Harry and TG near the end, several times you can see when TG hits Harry that the spade bends. (01:21:15)
Revealing mistake: In the letter to Mike Gallagher attached to the newspaper, subscription is misspelled. Sally Field is a reporter, so she should have caught that. (01:19:43)
Revealing mistake: The first time David werewolfizes, we're treated to the complete process... hair developing, bones painfully lengthening and twisting... and the torso of the actor very visibly halfway in the floor while all this is going on to the full-body werewolf prosthesis. Oh for computer graphics at the time to erase that detail of the process.
Revealing mistake: When Da Silva has finished shooting on the police firing range, the camera does one last shot of the target and you can see the squib detonator wire hanging from the hole that's just been created in the head area of the target.
Revealing mistake: When John Jaffrey is lying dead in front of his medicine cabinet, he is still breathing.
Revealing mistake: When the photographer is shot by Thana, his blood can be seen being thrown from offscreen. (00:36:54)
Revealing mistake: Obvious stunt doubles replace Cameron and Kim when they run from the telephone box just before it explodes. (01:20:09)