Visible crew/equipment: After MacReady says, "The generator room," toward the end of the film, he, Garry and Nauls walk down a flight of stairs. Then Garry and Nauls walk down a set of three steps whilst Mac is holding a flare. As they walk the shadow of a guy holding a boom mic is clearly visible on the floor. (01:30:05)
Character mistake: The last time Doc tries the defibrillator on Norris, he uses it on the abdomen instead of on the chest. He also positions the pads incorrectly. They should be placed diagonal, with the heart in the middle, not horizontal.
Plot hole: As the gun-toting Norseman approaches the buildings, Garry smashes the single-pane window with his handgun. It is inconceivable that the glazing in a structure near the South Pole would be single-pane glass, that would provide minimal insulation and which could be broken so easily.
Plot hole: It's never explicitly stated or shown that the Thing reproduces with each victim until the movie is nearly over (when Palmer infects Windows). Most viewers figure it out from the context, but it's unclear just when and how the characters themselves have come to this conclusion. This was an inadvertent result of an editing decision and a visual goof: there is a deleted scene in which Blair explains much more directly that the Thing multiplies according to how many victims it takes, and in its place in the final film is a scene containing a computer simulation that director John Carpenter acknowledges was a failed attempt at explaining the organism's life cycle.
Suggested correction: This isn't a plot hole. It's explained in the computer scene that the entire world population would be infected 27,000 hours from first contact. That only makes sense if the organism reproduces. Even without that explanation, there's no plot hole. The plot still works. The characters come to a conclusion. They might have worked it out, guessed, or simply be wrong. Just because that's what they believe it doesn't make them correct.
True, it has "the effect" of a plot hole more than it literally is one in itself, but it's the closest category for a pretty unique expository failure for a major studio film; one confirmed to have been a total goof in the production. All we have for most of the film is the implication of the word "infect" going up against VERY clear and misleading exposition of the Thing's nature. I'll consider changing the type to "Other," but I feel strongly it should be represented.
Continuity mistake: When they are all outside and MacReady has separated the three most likely suspects and orders that they be tied down and tested, he comments at that time that they are to be hit by a storm in six hours. Cut to the scene where Mac is dictating into his recorder and he comments that the storm has been hitting them hard for 48 hours. However it is the same night and at best, maybe only an hour has passed.
Continuity mistake: When Mac is locked out of the complex by the rest of the team, who think he may be a 'Thing', Childs uses an axe to try and chop open one of the doors, leaving a HUGE hole in the middle of it. Later Childs returns to that same door and the hole is significantly smaller and at a completely different location on the door.
Visible crew/equipment: At the end of the film, where MacReady is about to fight 'the thing' you can see the shadow of a guy holding a boom mic, on the ground just behind him.
Factual error: In the kennel scene, MacReady fires at least 7 shots from a pump shotgun. That particular shotgun can only hold 5.
Continuity mistake: When the crew is outside and they're going to lock Blair in the tool shed, you can see someone nailing wood across the window on the front of the shed. The pieces of wood are horizontal. In the next shot (inside the shed), if you look at the window in the background, the strips of wood are vertical. When Mac goes back outside, the wood is horizontal again.
Continuity mistake: Each man only dribbles a few drops of blood into the petri dishes as their blood samples. But when the test is administered, there is a lot more blood in each dish, enough to cover the entire bottom.
Continuity mistake: When the Doc and Kurt Russel enter the burnt Norweigan building the door closes itself behind the Doc. It closes and opens several times over the course of the scene.
Revealing mistake: When MacReady burns the one "Thing" with the split head, in one shot it walks by MacReady in the foreground, and you can tell in that shot that it is just a still dummy burning, as it isn't moving at all. It just sort of floats past with its arms at its sides, while in the previous and next shots it is wildly moving around, arms flailing.
Continuity mistake: When the three men are shown finding the UFO from the front, their hoods are down. In the next scene, from behind, their hoods are over their heads.
Continuity mistake: When Kurt Russell first looks at the chess game, amount of ice in his glass changes between shots.
Other mistake: When Blair goes crazy with an axe, they put him in the tool shed and Doc injects him with something to calm him down. The problem is: Doc injects him in the inner elbow, but wipes the upper arm as if that's where the injection went. Plus you only inject in the inner elbow when you want something IV, but there was no tourniquet, no searching for a vein. It should have been given IM, into a muscle, like the upper arm.
Factual error: At the beginning, MacReady dumps a tumbler of ice and scotch into his computer, which spews a shower of sparks as it shorts out. No electronic device, not even an old 1980s personal computer, sparks like that when shorted out. It simply goes dead.
Visible crew/equipment: When we see the huge dog alien, right before Childs burns it, a crewemember controlling the puppet is seen on the center of the monster's head.
Continuity mistake: When Kurt Russsell first goes to the crazy guys' shack, he puts a bottle down with the label facing forward. When he leaves it is facing the other way.
Factual error: If you are at or near a pole, aka Antarctica, you either have 24-hour daylight, 24-hour night, or a kind of continual dusk-like condition. You don't have bright day and dark night at the same time.
Character mistake: The spaceship is much deeper in the ice than frozen thing, indicating it was buried a hundred thousand years after the spaceship landed. Norris' calculation of the age of the spaceship wouldn't apply to the thing, which was hardly buried at all, by comparison.
