When David begins to play Globalthermonuclear War, you hear the computer voice say the words as they appear on the computer screen, however, when it asks him to list primary targets, the screen also says "by city and/or county" yet the voice cuts out without saying that.
When David is being held in the examination room, the guard, a Staff Sergeant, continually tries to flirt with the nurse. The nurse is a Second Lieutenant. Relationships are not permitted between officers and enlisted members. Nor would a Staff Sergeant try, to pick-up, make sexual innuendo, flirt or engage in that kind of conversation with a Lieutenant. Career-ender. Works the other way as well.
When David requests the number for Protovision from the operator, he's given a number with a 555 prefix. He also requests other prefixes for the area and is given four more, but when he sets up his autodialer, he only uses the four additional prefixes and neglects to include the 555 prefix in his scans.
When David is asking about the list of games that he printed out earlier, he asks Jim why the list has games such as checkers and backgammon. However when David was printing the list of games, backgammon was not one of the listed games.
When Joshua begins running through the war scenarios, the first one shown was "U. S. First Strike" and "U.S.S.R. First Strike" was next. On the screen showing the scenarios it had run, "U.S.S.R. First Strike" was listed first and "U.S. First Strike" came second.
The code to launch the missiles is "CPE1704TKS" when displayed
on the big screen and on most of the launch consoles, but it is shown as "JPE1704TKS" on one console shown in closeup in the sequence where the WOPR is attempting to determine the launch codes itself.
When David and Jennifer are on the island trying to find a boat to leave the island, Dr. Falken comes in a helicopter. When they show the ground shots, it is pitch black out, but when they show the helicopter, the sun is either setting or rising in the distance.
In the first dialog between David and Joshua - when David is typing the line "People sometimes make mistakes." - we see the last word typed correctly. Later we see the whole screen with that same word typed "mistak".
As Joshua asks David to choose a country to play, you see a two (representing the Soviet Union) already typed in. When they do a close up of the screen, David is typing in the two that was already there.
After the Soviet ICBM salvo is underway, a Soviet sub-launch detection is reported. The camera shows the screen, on which 14 subs (7 in the Pacific, 7 in the Atlantic) had launched their SLBMs simultaneously. In the scene before the impact of the Soviet warheads, however, the screen shows only 7 SLBM launches (5 in the Pacific, 2 in the Atlantic), and based on their distances from the target, they were launched at different times.
When David tries some of the numbers his autodialer has found, there are numbers with the 936 prefix listed. His autodialer hadn't dialed any 936-prefix numbers yet as it hadn't even finished dialing all the numbers in the 767 prefix.
In the second scene, as the teacher is reviewing the test answers, he reads question number two and question number four. Question number two had just been answered but not confirmed, while Question number three had been omitted or glanced over entirely without any explanation.
Jennifer is already in the classroom before David arrives without her test while the rest of the class already has their test in front of them. This was obviously done deliberately by the director to show the audience she received an F.
When McKittrick is talking to his secretary in the hallway before the goes to a meeting, he takes out his gum and puts it in her right hand. Then after the edit she puts the gum in her own mouth, but from her left hand.
When David first places the phone receiver on the modem he puts it on with the cord to the front; all other times he puts it on with the cord to the back. At all times he activates it by the button on the front.
The scene in which one of the radar analysts is asked to report activity showing Soviet submarine deployment, he says, "22 Typhoon-class submarines departing Petropavlovsk, turning south bound at Nordkapp." However, the screen displays submarines around a map of the Kola Peninsula in European Russia. Petropavlovsk is located on the Kamchatka Peninsula in Asian Russia. The location shown on the map is accurate, however, as all of the Typhoons were based at Nerpichya Base which is located on the Kola Peninsula.
Juse before the junior crewman "enables" the missiles a list of geographic coordinates (target locations?) appears on the video feed of the missile in the silo. The coordinates are all for locations in the Pacific Ocean. Since targeting data is preselected, this couldn't be the location of Soviet submarines.
In the beginning of the movie when the missile silo crew arrive at the Security Police post to sign in, there is a USAF Security Police Chief Master Sgt that is behind the desk and has them sign in on the roster sheet on the clipboard. A Chief Master Sgt is the highest enlisted rank in the USAF (8 stripes)and not only would a person of this rank not lower himself to perform a task as petty as to sign in personnel onto their post (a function normally handled by an Airman 1st Class, a 2 striper), but he would not even be at the silo, to begin with. The highest ranking supervisor to be there would be a Staff Sgt (4 stripes)
When WOPR is searching for the launch code, it is shown to be
able to lock onto each digit individually. In which case, it would only take 360 tries (one for each letter and digit), to definitely find the entire code.
After David is arrested, the next scene is at NORAD where a tour group is being escorted. The escort asks a woman with a camera around her neck to sit in the command chair. A visitor would not be allowed to bring a camera into NORAD.
After David hangs up the modem, disconnecting from the WOPR, his screen is shown with the game countdown continuing. Actually, in the 80's when a remote terminal was being used to connect to another computer, screen updates such as this halted when the call was disconnected, the countdown would have "frozen" on David's screen (continuing only on the WOPR).
When it is stated that "22 Typhoon class" submarines are departing. Only 6 Soviet Nuclear Ballistic Missile Submarines of this class were made. ("Typhoon class" were officially called "Project 941) were ever built. In 1983, the number would've been even fewer, as these six were built over an 8 years period (1981 - 1989). All of the Typhoon Class were based at Zapadnaya Litsa (Nerpichya Base) about 45 miles from the Norwegian border.
Despite the DVD commentary and popular belief, Defense Conditions (DEFCONs) actually do go from 5 to 1 as the situation worsens. DEFCON 1 represents imminent or ongoing attack on the US by a foreign power, while DEFCON 5 represents normal peacetime operations.
In the 1980s it was not permitted for any Department of Defense computer with classified information on it to be connected to external communication equipment. It would therefore be impossible to dial in as shown. However, during a scene, the military technician exclaims that the phone company "screwed them", implying an external contractor allowed the connection against request and policy.
As the WOPR is obtaining the launch codes, the missiles are shown to have the engines spinning up with the sound of a turbine engine. In the case of a Titan missile, this could be correct, because a Titan has two fuel components: Hydrazine and Nitrogen Tetroxide, which are pumped together by a turbine pump that is in fact powered by small amounts of these propellants. When the turbo-pump is on, it forces large amounts of the fuels together which spontaneously burn. When the pump stops, so does the engine.
When the relief crew arrives at the silo it appears they are in a snowstorm, as they are wearing heavy winter parkas. In the opening NORAD scene the guards are all in shirts - no jackets. This is unsurprising; US missiles are in many states, including North Dakota, where the winter scene likely took place.
When David makes the reservation for Paris, he does so using Jennifer's name. Later, McKittrick asks who he is going to Paris with, but if he had found the reservation, he would have already known about Jennifer as well.
The goof items below may give away important plot points.
When Joshua begins searching for the launch codes on the big screen at NORAD, Falken approaches the screen alone and sees the countdown has already started. But, when David and Jennifer join up with Falken at the screen, the countdown numbers are not reflected on the three of them. Halfway through the scene, the numbers on the giant screen reflect on them showing that the countdown started twice.
When Professor Falken is flying the remote controlled pterodactyl, he lands it is some relatively tall (about knee high) grass. When he walks over to retrieve it, the grass the pterodactyl is sitting on is very thin and low-cut.
Just after Lightman initiated the tic-tac-toe game with zero players (computer versus computer), the main WOPR computer technician Richter is seen at the WOPR-computer checking out the readout. A second later he is heard in the war-room, next to Lightman, saying: "It must be caught in a loop. Its drawing more and more power from the rest of the system". Yet Richter was present in the war-room just a fraction of a second before the scene switched to WOPR and his appearance there.
During the final sequence when Joshua/WOPR is trying the figure out the launch code, the sequence is shown in real time. When the statement is made "1 minute to impact", it is approximately 1 minute and 40 seconds later when impact finally occurs.
When David is being arrested by the FBI, he is brought to NORAD. While NORAD is a military installation and not affiliated with the FBI, given that he is immediately brought to McKittrick and the others, clearly McKittrick asked to meet in person the teenager who'd hacked into NORAD.
When the facility is being locked down and the door closes after David, Jennifer, and Falken rushed inside, the next segment shows the locking bolts being engaged their sockets, locking the door. There are four distinct sets of bolts shown (moving up, down, left, and right), presumably securing all four sides of the door. Four distinct 'clangs' are heard as the bolts bottom out in their sockets. However in the wide shots, the door only has two independent sets of bolts - one on the left and one on the right, none on the top or bottom.