
Character mistake: When 007 is interrogating Professor Dent at Miss Taro's house, Dent attempts to shoot him when he asks "who are you working for?" But a minute ago, his gun ran out of ammo when he was shooting at the fake 007 in the bed. So there is no point of picking it up and trying to shoot him. Also, when this happens, 007 says "that's a Smith and Wesson. And you've had your six." This is incorrect, as Dent carried a Colt M1911. However, he did fire six shots before running empty, which is one bullet less than the magazine capacity of an M1911. (00:56:30)

Character mistake: While he is describing his origin, Dr. Manhattan mentions a circulatory system appearing at a military base. However, what is actually shown is a nervous system, as it depicts a brain and spinal cord.

Character mistake: When Lt Gannon is in the dogfight with the Russian jets, he announces that he is deploying "chafe and flares." The term is spelled and pronounced "chaff", and any pilot would know that.

Character mistake: When Malloy first visits Frannie in her apartment, he says the girl was killed on the 15th, but when Frannie is in the cop car for the first time, Malloy's partner says it was the 11th.

Character mistake: Joan Clarke pronounces the name of the mathematician Euler to rhyme with "ruler", when in fact it is pronounced "oiler."

Character mistake: Nick states that Wall Street was originally a wall (correct) built to defend against the British (incorrect). The original wall was a wooden palisade built in the 16th Century to defend the Dutch colonists against invading natives and to prevent livestock from wandering uptown.

Character mistake: There is a misspelling on the cover of the issue of Forbes magazine shown in the presentation about Stark's life. It reads "Tony Stark takes reigns at 21". The correct spelling of the word is "reins". Stark may "reign" at Stark Industries but he would take over the "reins" of the company.

Character mistake: When Carolyn first addresses Imam, she quite obviously pronounces his name "ell-mom," as though the capital I in his title were a lower-case L. It should be pronounced "ee-mam". We distinctly hear Ali call out his name in this fashion after the ship crash lands on the planet.

Character mistake: The information on Walter's "patient information sheet" lists his address as 5962 Delco St but numerous shots indicate his house number is 238. (01:03:25)

Character mistake: An unloaded automatic pistol is much lighter and balanced differently than a loaded one. When McClane hands "Bill Clay" (Gruber) the empty pistol, a terrorist of Gruber's credentials should pick up on the odd balance (I notice that difference, and I very rarely even pick up a gun).
Suggested correction: This presumes that a person can notice the difference between a fully-loaded pistol versus a pistol that is empty, which makes sense. However, it would be much more difficult for a person to tell that a gun is completely empty versus one that only has one or two bullets loaded. Since Gruber has no way of knowing his ruse didn't work, he doesn't believe McClane would have given him a completely empty gun. He obviously believes there is at the very least one bullet in the gun. He's not planning on getting into a shootout with McClane, he is just planning to threaten him and he certainly doesn't need a fully loaded gun to do that.
Suggested correction: It's easy to tell the different between the weight of a loaded vs. unloaded pistol, but given Hans had never held the pistol before, he had no way to compare the weight. Unless he regularly handled that particular model of pistol (unlikely, given his pistol is a completely different make and model) he would have no point of reference.

Character mistake: After the first attempt by the kidnappers to get the ransom money, they tell the FBI to bring the money behind the Foo Chow restaurant. Clive gives Carter and Lee the exact same destination. Why in the world would kidnappers give the FBI a drop-off location exactly where they are based?

Character mistake: Close to the end, Madison is looking over the H.A.L.O. list on her laptop. When Dylan's profile pops up, her last name, Saunders, is misspelled as Sanders.

Character mistake: The bank robbers send out a hostage and put a drawer around his neck with a note. The drawer is bugged and the bank robbers can monitor the police. The police just leave the drawer lying around on the table for half of the movie inside their mobile headquarters. This drawer should be in a forensic laboratory being checked for fingerprints and similar.

Character mistake: After the Congressman is killed, the killer dumps pills on the floor of the car. Then the car is then rolled into the river. At about 15:07 the news reporter mentions that the Congressman's heart pills were found in his lap. This would be impossible because the pills and bottle would float and the pills would dissolve in the water. (00:03:45 - 00:15:05)

Character mistake: At the very beginning of the film, when Hannibal Lecter is serving dinner to his guests, one diner asks "what is this divine looking amuse-bouche" when she and the other guests have a full plate of food. An amuse-bouche is a single bite of food meant to be served at the beginning of a meal, not a plate full of food. Lecter's guests would be better educated.

Character mistake: Early in the movie Cary Grant is on the beach and is told he has a phone call. While conversing with Bertani, Cary Grant has the handset backwards - he is speaking into the earpiece and listening to the mouthpiece where the chord is attached.

Character mistake: Engine #1206 is instructed to take the nearest siding upon hearing the news of the oncoming train. Frank does the maths and determines that they will not fit into that siding. He states the siding being 4011 feet between signals, with about 2500 of actual usable space. Engine #1206 with 25 cars would only equal 1580 feet, giving them more than enough room to clear in the first available siding.The average length of a railroad car is 60 feet. Even if the cars were considered "long", total 25 cars would have fit into that siding.

Character mistake: When the plane is speeding down the runway at the beginning, a female flight attendant is seen walking, and Kyle is seen buckling her seat belt. Everyone would have been sitting down and buckled in at this point.

Character mistake: When Marion is calculating how much she spent her math is wrong. The movie shows 400000 - 4036 = 395963. It should be 395964.

Character mistake: On the handwritten label Bond finds, Bratislava is written Bratislavia.