Factual error: When the infected Palmer starts his transformation into the Thing, he has a series of fits and the creature 'falls', or leaps upward onto the ceiling. Watch closely...you can see a piece of paneling also 'fall' upward, when it should have fallen down. (01:23:20)
Factual error: The "big giveaway" that happens at 9pm across the whole country would have to happen at least five different consecutive times due to time zones. The "big giveaway" in the most eastern time zone would be successful, but further west it would be earlier than 9pm.
Factual error: In the first story, Father's Day, it is dark at 7:00. In the middle of June, the sun stays up until at least 8. Or even 9 up north.
Factual error: The movie is set in 1974. The Sony walkman was introduced in 1979, yet Sonny is seen listening to one.
Factual error: Jason picks up a red hot poker from the fireplace and it sizzles. Fire pokers only sizzle if they touch something. (01:08:56)
Factual error: During the climax of the film, coffins from the cemetery below rise out of the ground. Only problem: they're rising vertically. Coffins are laid horizontally.