Factual error: MacKenzie is referred to as "Gunnery Sergeant". This is not a rank used by British and Commonwealth forces. He actually wears the rank insignia of a Flight Sergeant.
Factual error: Slater had close to a dozen sticks of dynamite on him. At the very least they should have knocked Winona Ryder down, and made her deaf for a few days.
Factual error: During the scene where the platoon is stopped by the large lake on their 15 mile hike Sgt. Toomey says, "You must have been in the first World War." WWI and WWII were not referred to that way until years later.
Factual error: The address on Claire's business card reads 514 West 43rd St. When Frank gets there, the street sign is for 3rd St./900 East block. The sign on the building reads "9th Street Temporary Shelter". Along with these discrepancies, taking into consideration that 3rd St. may be the cross street, WEST 43rd would not cross 3rd St. EAST, as they are on opposites sides of Manhattan. Even if the '4' on the sign for 43rd St. were somehow obliterated, 514 still would not be on the 900 East block. (00:53:10 - 00:54:15)
Factual error: When Judge Reinhold is in the department store playing the Space Invaders video game, and one of the men chasing the skull comes to talk to him, Judge continues to play the game, so the man stands between him and the screen in order to get his full attention. If you watch the screen, the game actually continues to play on.
Factual error: There is no way the DMV will pass one twin based on the fact that his twin passed, even though they ended up taking his license. The mistake was giving it to him in the first place based on the fact his twin passed.
Factual error: At the end of the movie Tess gets a job at Trask. Her secretary tells her that she can get her schedule on the PC by pressing shift + s. That would result in a capital S only - what she probably means is ctrl + s. (01:44:15)
Factual error: The damage done by the hobgoblin-induced fantasies is real, as seen several times in the movie. Kyle's car runs off a cliff, Nick's grenades really explode, etc. Nick is in one scene set ablaze by throwing himself on a grenade, and is completely engulfed in flames from his head to his toes. But he shows up in the last scene with nothing but a few minor burns on his forearms and a pair of crutches (that he immediately discards). His hair and eyelashes are not even singed.
Factual error: When Johnny shoots the taxi with some kind of cable and pulls it backwards, the rear tires are shown to be spinning in an attempt to move. The taxi is a Chrysler K-car which is front wheel drive.
Factual error: When Arnie and Devito are stealing the car and Devito sets off the car alarm, Arnold picks up the car from the back end to stop it. If you watch the wheels you will notice that they don't shake or move at all when Arnold sets the car back down on the ground. (00:27:23)
Factual error: Sean Connery's character is the Provost Marshall for the Presidio, he would not be wearing the MP sleeve placard as he is in the scene at the Officer's Club. He also wouldn't be running around wearing a Field Jacket with the collar up and it unzipped. You wear the jacket correctly or not at all.
Factual error: "Kemo" is in the kitchen preparing food while everyone is studying. We see him putting raw meat (brains) in a pan, and then in real time we see him having a discussion with Pancho, and Pancho walks out. Kemo then says the food is done and asks if anyone wants some - but there's been no more than 60 seconds since he put it in.
Factual error: Shooting at a gas tank with buck shot at 50 meters distance will not make it explode (it likely won't even dent the surface), and lead pellets do not cause sparks when they hit.
Factual error: The sequence showing the moon is incorrect as it shows the Moon as it looks from the northern hemisphere. It should be inverted.
Factual error: This is a summer time movie but you can see brown leaves everywhere in the film like its the beginning of fall.
Factual error: Bob is in prison and he still has his gold ring on his right hand ring finger. Prisoners are not allowed to keep their personal property while in prison. (01:17:00)
Factual error: When John Candy throws alcohol on the fire after his bear story, there is a big explosion, but no amount of alcohol could cause an explosion big enough for a mushroom cloud, only gas or lighter fluid (especially the only small amount that is in John Candy's glass he's holding the glass is barely full and mostly ice.).
Factual error: For most of the movie you can see mountains and large hills in the background. The movie takes place in Kansas and almost all of Kansas is flat.
Factual error: In cooking class, the teacher said "two stalks of celery" and Michael handed Lorna one stalk, which she started to separate. One "stalk" is actually the entire bunch (or head), which is made up of 8-10+ "ribs" connected at the bottom. Two ribs will equal about one chopped cup - about right for the tuna walnut casserole made with one can of tuna. Americans typically use the word "stalk" interchangeably with "rib", calling a single rib/ stick/ branch a stalk, but the stalk is the entire bunch. (00:37:02)
Factual error: The Los Angeles cops pursuing Lulu, Peaches, and Darlene in Mexico couldn't arrest them due to this being a foreign country where they wouldn't have jurisdiction.