Factual error: If the Russian cosmonauts need special suits to survive out in space, so should Lacy when she is abducted by Nuclear Man. (00:02:50 - 01:20:20)
Factual error: Austria is famous for its mountains and ski resorts, but certain parts of Austria are quite flat. And the border region between Bratislava and Vienna is VERY flat. No chance to cross the border over a mountain with a ski resort like shown in the movie, unless you take a 600km detour with three more border crossings.
Factual error: The heat from Dutch's body would warm the mud up in a matter of seconds (tested by the Mythbusters). It doesn't even cover all of his skin or his eyes. And the Predator isn't filtering his input for only large heat sources. His normal vision tracks in on a rat hiding just above Dutch.
Factual error: At the beginning of the movie, Steve Martin is trying to catch a cab to LaGuardia at about 5:30PM. In the movie, it's still daylight, whereas in reality, NYC is pitch black by that time of day - the sun sets at about 4:30PM in late November.
Factual error: Hot Air Balloon's have no lateral control. They fly in the direction the wind is blowing, so it's rather impossible for two hot air balloon's very close to each other to be flying in different directions, let alone fly exactly to the desired locations.
Factual error: In the beginning of the movie when they are in the kitchen, over on the TV you can see an episode of the Price Is Right, but it was Friday evening. The Price Is Right is on in the morning, so it could not have been playing live on the TV at that time of day.
Suggested correction: The Price is Right did night shows in the mid 80's, specifically from 1985-86.
Either you're referring to "Nighttime" The Price is Right, which ran for one season from '85-'86 or "Primetime" The Price is Right from '86. Neither of these two are what is on the TV in the scene. "Nighttime" was hosted by Tom Kennedy and "Primetime", Bob Barker wore a tux. In the scene, we see Bob Barker in regular clothes.
Factual error: In the written introduction, it states that it's the late 12th century, and Richard II is king. "Lionheart" was the nickname of Richard I who ruled in the late 12th century; Richard II didn't rule for another two hundred years.
Factual error: Grizzly bears and wolves are within the film. In reality, both of these animals were extirpated from Oregon at the time of the film's release.
Factual error: The Joes chase Cobra into the snowy mountains and attack inside the weird cave. One of the Joe's vehicles splits to a driving section, and Road Block flying up in a little fighter. Road Block is holding a large rifle with both hands, yet the fighter goes up and turns around and begins flying at his control but he never touches a steering wheel or anything. Just his big gun. And he does not speak so no voice commands are given. How is he flying with no hands? (00:19:40)