Factual error: During the war games they have Jefferson pose as a major in order to facilitate the commandeering of the ambulance and the jeep. Regardless of their personal feelings in the matter the ambulance crew and the driver and troops in the jeep would be perfectly aware that no black man would ever be promoted to a position of authority in an otherwise all white command. We may find it repugnant today but the US Army was rigidly segregated during World War 2 - and it stayed that way until 1948. Jefferson may have been inducted into a special unit like the Dirty Dozen but considering that the future of the entire mission is riding on their success at the games, throwing it all away like that makes no sense at all.
Continuity mistake: In the scene where Coco tears up the photo of Luke with the women, he tears it carelessly, starting with the upper left corner. The end shot of the movie shows the same photo, reassembled, showing a neat, cross-wise tear, with the center of the tear directly over Luke's heart.
Continuity mistake: Mrs. Robinson picks up the phone to call the police on Benjamin who has broken into her house but if you look closely she never dials the phone. (01:35:10)
Suggested correction: Since we never see the police come in, we're not for sure she actually called them as Mrs. Robinson is known to lie and manipulate. All we hear are tires screeching and as we see no police pursuing him, it's unlikely.
Continuity mistake: In the wide angle shot of Chief Gillespie approaching Virgil Tibbs at the train station, there is a dog on the platform, in between Gillepsie and Tibbs. In the next shot, a closer view of Gillespie approaching Tibbs, the dog is gone.
Revealing mistake: When the farmer is going to shoot the sign the bank put up, you can very well see the mark where the hole is going to appear.
Revealing mistake: In the scene where King Arthur expounds on the joy of his kingdom, he has a Band-Aid on the back of his neck. (00:21:00)
Continuity mistake: There's a scene where Audrey Hepburn's husband Sam is leaving their apartment. Standing on the pavement outside he hails a cab, which pulls up through a (quite sizeable) puddle, splashing him with water. Opposite him on the other side of the road are parked two cars and the villains' Volkswagen van. There's a quick cut-away exchange of "pleasantries" between Sam and the cabby before it drives off. The next shot has the villain (Richard Crenna) emerging from the van, crossing the street, and making for the door to their apartment, only all of a sudden the puddle has disappeared, as have the two cars which were parked behind the Volkswagen van.
Revealing mistake: At the end when the class are having their dance, the band manage to play without any amps, speakers or mikes. We even hear keyboards, despite no-one playing any.
Continuity mistake: When Spencer Tracy backs into the blue hotrod, the cars end up kind of sideways. In the next shot it shows the cars at a 90 degree angle touching. Then in the next shot it shows them sideways again as he pulls away.
Factual error: In the final scene of the movie Elvis and Shelley Fabares are driving in his sports car along a seaside highway outside of Miami Beach. There are mountains along the coast in the background. There are no mountains in Florida.
Plot hole: At the beginning of the movie, Reese (and Walker) rob from a "drop" at Alcatraz. Reese uses that money to pay off "The Organization." At the end of the movie Brewster tells Walker the only place to get cash is at the drop. "The drop is the same but the location has changed." Brewster receives the money at the drop. This makes it clear the original drop was stealing from "The Organization." Why would Reese be able to pay off "The Organization" by stealing their own money from them?
Factual error: The narrator near the beginning says Al Capone was born in Italy. He was actually born in Brooklyn NY.
Continuity mistake: At the beginning, right after the opening credits, Old Timer picks up a gold rock. When he first picks it up, we see a close up shot of his hand holding it only an inch or so above the ground. The very next shot a second later, from the side, shows his hand holding the gold instantly a foot or so above where it was before.
Factual error: In the scene when the two criminals are in the hardware store, two vehicles are parked outside that are clearly late 1960's automobiles, despite the film being set in 1959. (00:15:25)
Factual error: When the ambulance arrives the policeman, at the crash scene, is wearing a City of London Police helmet (different from the Met) yet he is in a Metropolitan Police area.
Other mistake: The villain's plan is to impersonate along with his large crew a platoon of the Mexican army. He already captured the soldiers and has them incapacitated, all he needs to do is take their uniforms. Instead of doing so, though, he mows down the whole lot with a heavy machinegun. When it's time to put on the show, everyone wears nice and tidy white uniforms.
Continuity mistake: Alain Delon tries on some jackets. He finds a briefcase and opens it. You can see the contents of the briefcase before it cuts to a closer view; in this closer view, a stack of letters moves, and an orange case vanishes entirely. (00:27:00)
Factual error: When Miriam is pacing, waiting for Tony to come home, she is listening to Tony singing "Come Live with Me" on a reel-to-reel tape recorder, but the recorder has no speakers, either built-in or separate.