While Agent Goodspeed is describing the horrible effects of VX gas, the part where he says "it melts your skin off" does not match his mouth movements, and sounds different than the rest of the audio (since real VX gas does not melt skin (see above), it was probably added to make VX gas seem scarier to the audience).
When Goodspeed first commandeers the Ferrari, it's clear that he isn't familiar with Ferrari's gated shifter system in the F-355. He shifts into 3rd gear and promptly lays rubber. Though the 355 has ample power to start in 3rd gear, the smoky burnout had to have been accomplished in 1st.
Captains Frye and Darrow are constantly referred to as "soldier", something no Marine would ever stand for. This is because they are most likely former U.S. Army Rangers as the black beret, then the uniform item that distinguished them as such, indicated this.
When the Ferrari crashes through the parking meters, the indicator lights on the bumper have disappeared (presumably as this car is a mock up), but in the next shot of the Ferrari from the front, the lights have reappeared.
The plane which rolls out of the hanger is a two seat F/A-18 Hornet, yet all aircraft in the flight squadron are single seaters. This plane has no tail markings such as aircraft registration number and squadron ID.
The disguised Marine that shoots the two guards inside the weapons depot is wearing gloves. Later, when he drops the VX gas canister, he's not wearing them. Although it's possible that he took them off, even if he did, he's shown wearing them a second later (when Major Baxter yells "Evac!"). Then it shows him banging on the door without them on.
During the shower room scene, Major Baxter who is on the immediate right of the General is seen carrying an M16A2 rifle. A few frames later his weapon magically transforms into a Colt Commando. A frame later his weapon transforms back into an M16A2. The final frame shows him holding his Colt Commando.
After Mason talks to Jade, Womack Steps forward and starts to moan about damages to San Francisco, his jacket changes position over his injured shoulder. He lifts his arm in a motion to show how he's been injured and his jacket slides off his shoulder. When the camera cuts back to him his jacket is normal again.
After the trolley car destroys his Ferrari, Goodspeed steals a dirt bike. When he knocks the rider off, the rider falls to the left side of the bike. However, in the next scene he is on the ground to the right of the bike.
Cpt. Darrow's main rifle changes throughout the film. During the shootout in the shower room, it is a M16 (SP1) rifle with a "slab-side" upper receiver (no forward assist) and an M203 grenade launcher. During the lighthouse scene when Darrow confronts Goodspeed (Nicholas Cage), his rifle switches from this M16/M203 to a Colt Commando CAR-15 carbine fitted with an M203.
When Mason is being held in the interrogation room (while being tricked into helping with the operation) we see a monitor in the room behind the mirror on which Mason is seen - the image on it suggests a camera pointing at him directly from the front, at the same height as his head, but as we see in the shots from inside the interrogation room, the only thing in front of Mason is the table and the door, no camera anywhere in sight (we also see people coming through the door several times, revealing that there isn't a camera outside it either).
As the police chase comes down the street towards the parked car and telegraph pole that Mason will eventually hit, there is only one FBI Suburban and one SFPD patrol car following him (along with Stanley's Ferrari and the two FBI sedans). In all other scenes during the chase, it is clear that there are three patrol cars and two Suburbans in the pursuit. They reappear when the FBI sedans crash and all come to a halt.
It is obvious throughout the pursuit that there are only two unmarked FBI sedans involved. However they continually change between a Chevrolet Caprice and Ford LTD-Crown Victoria (the combination in most scenes) to two Chevrolet Caprices. This is most evident when both units roll trying to avoid the telegraph pole - on approach they are the Ford and Chevrolet, but when crashing both are Chevrolets.
During the police chase, the two FBI sedans are shown as having two agents each in the front (one shot shows three in the LTD-Crown Victoria), however from the moment they come over the hill and approach the pole/parked car Mason hits and then crash, there is only one agent in each.
When the first unmarked FBI unit smashes through the wreckage of the VW Bug Mason drove over at the construction site, the vehicle behind it can be seen to be another unmarked Chevrolet Caprice (with push bar). In the next shot, it is the Ford LTD-Crown Victoria without a push bar. Two shots later, the first Caprice now has two patrol cars behind it and another unmarked Caprice is following those.
Mason tries to open his cell door by manipulating the door lever using the torn duvet cover. At first he hits the one opening the cell next to his own, and as he gets it right on the second try we see that the lever falls down as the door goes up. However, the lever that opened the first door is still in the upright position.
When Gen. Hummel is on the phone with the Pentagon stating his demands he tells Gen. Kramer and the others they have 40 hours, "noon - day after tomorrow" to deliver the money. Hummel contacted the Pentagon at midnight, so the deadline would actually be around 16:00 the "day after tomorrow".
Towards the end of the film the configuration of the Colt Commando CAR-15 rifles change. For instance, when Mason gives Goodspeed the CAR-15 from the guard he killed, it has an A2 upper receiver (shell deflector, A2 windage sight knob) and an SP1 lower receiver (no fencing around the magazine release). Later when watching the rocket launch, Goodspeed's CAR-5 switches to an all around A1-style gun with no shell deflector and older style sights. The lower receiver also has magazine fencing at this point. The same also happens with the other Marines' guns.
The launched missile is said to be launched toward a football game in Oakland. However, the next shot shows the missile flying over Candlestick Park in San Francisco, not the Oakland Colliseum. In fact, the missile is clearly shown grazing trees on top of Bayview Hill.
After Goodspeed is informed that it is not a training exercises, they show a shot of Pier 39 in San Francisco and show the FBI setting up their mobile command center. It is in an enclosed warehouse setting. Pier 39 is an open air area with restaurants, shops and lots of public area. Not inside a warehouse.
When the missile is launched, the radar operator states that the missile is headed toward Oakland. This is backed up by the map showing the missile's path from Alcatraz southeast in the direction of Oakland and the football game. However, when the missile clears the hill and the stadium comes into view, it is obvious that this is Candlestick Park in San Francisco and not the Oakland Coliseum.
When Womack first receives a telephone call from Hummel, he turns to his secretary and says "call the San Francisco office... it's seems like Alcatraz has just been reopened (19mins 40secs into the film)." The very next shot is an aerial view of the Pentagon. The lights are on at the Pentagon, but there is some daylight - indicating that it is either very early in the morning or later afternoon/early evening. However, the text on the screen then says "PENTAGON 11:58." Now this is impossible. At 11.58, it is either pitch black or full daylight.
VX in liquid form, as presumably shown in the film by the small balls containing the substance, does not take effect immediately. After absorption through the skin and/or mucous membranes, it takes approx 1 to 2 hours before visible nerve agent symptoms begin to show. However, if a person is exposed to the aerosol form of VX, effects are immediate. In either case, the symptoms of VX poisoning resemble more of a full-body seizure than a bubbling/melting of the skin. Atropine must only be injected into the heart when poisoning by the aerosolized version occurs. Otherwise, the atropine is injected into the thigh. Furthermore, Atropine is also poisonous to the human body when it's injected into the body before aerosolize exposure occurs, either case Atropine's main side effect weakens the human body to the point of incapacitation and would be in no fit state to diffuse a bomb or get up and run and wave flares as depicted in the movie.
During the chase, when Goodspeed crashes the Ferrari into the parking meters, several dozen coins spill out, including a good number of pennies. Modern San Francisco parking meters do not accept pennies (and have not in decades).
As the F/A-18s roll out of the hanger, the markings under the canopy say U.S. Air Force, but if you look just above the wings you can still see the VFMA markings indicating this is a U.S. Marine Corps jet.
When the SEAL team arrives with their miniature submarines at Alcatraz a view at the cockpit display a speed of 67 knots just before they arrive at the entrance. Under no circumstances can any submarine go that fast, and even if that were possible it would not be feasible to drive that fast just before the arrival, since it would be impossible to brake in time.
The unmarked Caprice that comes flying out of the hotel parking lot at the start of the chase has a front US Government license plate with the General Services Administration prefix G15, while another (that lands hard coming down the hill) has the prefix G13. Both of these are erroneous - G15 is an invalid prefix, while G13 denotes a subcompact sedan, which a Chevrolet Caprice clearly is not. Both plates should have a G14 prefix, which denotes a large sedan.
VX was not discovered by mistake. It was discovered by Dr. Ranajit Ghosh, when he did research on pesticides. It was not a failed pesticide either, it was used as a pesticide until 1954-55. It was however, withdrawn due to its high toxicity. From 1961, it was manufactured for weapons use.
The aircraft used to drop the thermite plasma are F/A-18 Hornets, which are normally US Navy or US Marine Corp jets, but they have US Air Force markings as do the pilots flying them. The Air Force flies F-15 Eagles, F-16 Falcons, and F-22 Raptors.
The AH-1 Cobra gunships used in the infiltration scene are not Marine helicopters, but rather the Army model. The Marine version is an updated model with twin jet engine propulsion turbines, the Army model used in the infiltration scene still uses a single jet turbine to turn the rotors. This can be seen by observing the single exhaust port instead of the twin exhaust on the marine model. During a Navy S.E.A.L. incursion marine helicopters would escort the transport helicopter, not Army Cobras as depicted in the film.
When the first missile is launched toward San Francisco, there is concern about it striking a stadium where a football game is being played. West Coast games have a 1pm start time for TV purposes, and generally do not open the gates until 12:15pm. If noon is the deadline, then no-one other then the players, stadium employees, and TV crews would be at the stadium. Yet when the stadium, Candlestick Park, the night lights are on, and the stadium appears full. The night lights would not yet be on.
As the Marines are patrolling, they continuously charge their weapons. While on patrol, it would be assumed that they would already have a round in the chamber. As a result, charging the weapon again would not only be unnecessary, but it would cause the weapon to eject a perfectly good round.
When Mason is with the troops in the basement of Alcatraz, he states that he studied the timing of the boiler that he must roll through. The question has often been asked why he wouldn't then just be able to open the door during his original escape. However, when Alcatraz was functional, the door may well have been guarded or locked from the other side.
Mason has been imprisoned for the past 30 years yet when he escapes he knows how to work a cell phone (reasonable, since it's not hard; he also mentions that he watched TV in jail, so he has probably seen plenty of examples) and modern scuba gear (which hasn't changed all that much).
The White House Chief of Staff refers to Gen. Hummel's Medal of Honor as the "Congressional Medal of Honor". It is simply called the 'Medal of Honor' and does not have the word 'Congressional' in it's name. While it is true that no one in the U.S. Military would use that incorrect term, that incorrect term for the Medal of Honor has been bandied about for a long time and many people who have never been in the Military know it by that incorrect name. Therefore, it would be feasible that the White House Chief of Staff would call the Medal of Honor the "Congressional Medal of Honor".
Whilst in pursuit of Mason after his escape from the hotel, Paxton states over the radio that he [Mason] is driving a black "Hum-Vee". A Hum-Vee (or HMMWV) is a military vehicle. The civilian model that was made by AM General, the manufacturers of Hum-Vees, was released under the brand name "Hummer". However, the term "Hum-Vee" is also popularly used to refer to the civilian brand.
Right before the Marines betray General Hummel, Captain Darrow refers to Gunnery Sergeant Crisp simply as "Sergeant". NCO's and SNCO's in the Marine Corps are always referred to by their full rank, i.e, "Gunnery Sergeant", never simply "Sergeant". Captains Frye and Darrow are, however, likely Army captains and not Marines (multiple evidences are given for this), and so they are not as immune to this mistake.
Despite having been unused for 33 years, all the mechanisms for the tracks and carts in the caves seem to work fine. The rope is also strong enough to halt a cart moving at moderately high speed, with the additional weight of two fully grown men on it and there is very little evidence of rusting, despite the incredibly damp environment.
When Mason brings Goodspeed and crew back to the Rock, he shows how he escaped by ducking under the heating vent, but to go back in he goes under the vent and then opens the door from the inside to let the crew in. If the door opens from the inside, why did he have to duck under the vent to escape?
Mason smashes through the one-way glass observation window of the interrogation room after scoring a circle in the glass. However, his elbow smashes a hole in the center of the scored circle. None of the glass that was scored cracked.
When the Ferrari finally is destroyed, it appears that it is simply a shell sitting over a chassis. The shell seems to almost jump off the chassis upon impact, indicating that it wasn't bolted in as it should be.
Throughout the San Francisco car chase scene, driver frequently turn their steering wheels as if they were on a narrow and winding lane when their cars are moving in a more or less straight or at least consistently curved line. numerous cars are also shown to explode after being hit at roughly forty to fifty miles an hour. Both are common goofs for the genre but happen so frequently in such a short space of time in this movie that it's worthy of a mention.
At several points in the movie, the Marines are firing M4s; sometimes they eject cartridges, but when you see a closepup of the captain firing at Goodspeed and Mason, there are no cartridges being ejected from the weapon.
In the morgue scene, when Mason shoots the marine's feet he is shown to be firing at an angle almost parallel to the ground and from ground level, which would result in the marine getting shot in the front of his boots. The resultant bullet holes are on the tops of his boots and explode outward - impossible from the angle of shot shown - revealing them to have been caused by explosive squibs inside the boots
During the car chase, Mason runs the Hummer into a telephone pole, knocking it over. Subsequently, two of the FBI chase vehicles flip over (one tries to cut his wheel too hard to avoid it and the other runs into a parked car). The driver of both cars is the same man.
When the tram crushes the Ferrari, the alloy wheels that come apart from the car are not Ferrari alloys (showing this is another mock up car and not a real Ferrari). These mock alloys can also be seen resting on the ground when Goodspeed turns to observe the crushed Ferrari.
When Goodspeed gets in the Ferrari and closes the door, you can see that it's the door of the real F-355. Later when the tram destroys the car, the door is that of the stunt vehicle and, understandably, not of the real Ferrari.
When driving the Hummer in San Francisco and swerving to avoid the old lady crossing the street, Mason hauls the steering wheel clockwise (from his point of view) but the car turns left, for which he would have had to turn the wheel anti-clockwise.
The scene when Goodspeed shoots the soldier choking Mason in the overhead cart. Mason tells Goodspeed, "I'm glad you didn't hesitate." They switch back to the dead soldiers' body and a close-up of his face and the soldiers' eyes blink twice slightly.
The goof items below may give away important plot points.
Before Goodspeed injects himself with the antidote, he activates the spring-loaded needle of the auto-injector, then manually forces the needle into his chest. Auto-injectors are designed to be placed it directly against the skin, so when activated, it propels the needle directly into the body. What he does in the film makes no sense, especially considering the amount of force a chest injection through clothing would require, and the fact that he's been weakened by nerve agent exposure.
After Mason pulls Goodspeed out of the water at the end, he is asked over the radio if the hostages are alive. Goodspeed replies "every one of them". While he could have confirmed that they were not hit by the bombs, he could not have possibly known that none were shot by Hummel's team in the last 24 hours, so he probably assumed this was the case.
When Goodspeed is talking to Captain Darrow in the lighthouse, Darrow drops his gun while taunting Goodspeed. When asked if he likes Elton John's 'Rocket Man' you can see him holding his gun when he responds.
During the standoff between Hummel, Maj. Baxter, Capts. Frye and Darrow, and Gunnery Sgt. Crispe, when Mason and Goodspeed are looking through the slot, Capt. Frye only has a 9mm handgun: however, once the shooting started, Capt. Frye shot at Mason and Goodspeed with an M-4 assault rifle.
After Hummel is shot, Goodspeed drags Hummel away from danger and is kneeling next to Hummel interrogating him. While Mason is providing cover fire, there is a glimpse of a crew member/actor darting across the room behind him.
During the final shootout after the soldiers mutiny against Hummel, you can see Hummel make a dive behind a wall. As he does this, you can see in the lower half of the screen the small blue corner of a mat that was used. Note that this is only visible in the normal TV format and can't be seen in the wide-screen format.
In the scene where General Hummel is shot, he flies backwards and his left leg momentarily comes into the picture. The wires used to detonate the squibs can be seen coming out of his left pant leg near his boot.
After Goodspeed and Mason have been captured, and it shows the words "52 minutes to deadline", that would make it 11:08 in the morning. When they launch the first rocket, the sun is really far down in the west, making it appear to be about 7:30 p.m., not 12 midday. When Hummel aborts it, it's blue sky. When Goodspeed launches the green flares, the sky changes from sunset to midday to sunset in about ten seconds. When he is rescued by the FBI, it's almost dark, about 9 p.m. But in reality, according to the deadline, it's only about 1 p.m. at most.
According to the movie Atropine should be injected directly into one's heart to neutralize the effects of VX poison gas. When Goodspeed injects himself with the Atropine he injects the needle in a spot too low to be his heart. It is more like he was injecting it into his stomach.
It appears that Goodspeed leaps to catch the rolling VX in his right hand, catches it in his left, then has it in his right again, but close examination reveals he quickly pushes the ball from one hand to the other.
Mason was captured in 1962 after hiding the microfilm. At the end of the movie Goodspeed, while viewing the microfilm, asks if his girlfriend wants to know who killed John F. Kennedy, which occurred in Nov 1963. Though this might be an anachronism, it's also possible that the FBI had evidence of the assassination plot prior to the actual event, and that is part of the information Mason stole. This would fit into the plot device of having the microfilm contain all of the FBI's cover-ups.
The scientists outside the gas chamber shout at the men inside to inject themselves "before your suits melt." Atropine is toxic if taken when exposure to a nerve agent has not actually taken place - taking it before the suits have melted would incapacitate the agents, but the suits were clearly breached when the scientists said otherwise. In addition, when Goodspeed takes the atropine at the film's climax, he is clearly weakened and only barely able to light the flares to recall the bombing.
At the end Goodspeed puts a glass sphere in the pocket on his chest. We do not see any measures taken to prevent it from breaking. But in the fight afterward we clearly see Goodspeed land on his chest. The same glass later breaks quite easily in the mouth of the terrorist. The same glass was shown (in the scene where Hummel's troops break into the weapons bunker to steal the missiles early in the movie) breaking quite easily from just rolling across the floor and hitting the wall!