After the West Virginia power station explodes and McClane and Farrell watch the electricity slowly shut down, there's a shot of an unspecified airport with the power going off. In that shot we see at least three Air Canada 747s taxiing or at their gates. Air Canada had already phased out and retired its entire 747 fleet at least two years prior to the year this movie was set (2007).
When McClane and Ferrell are shown driving to West Virginia in the stolen BMW, the interior of the car is quiet, as if all the windows are rolled up, but the passenger rear window is clearly shown to have been smashed to gain entry (and smashing of the window was a plot point), meaning the wind noise from driving on a freeway would have been substantial and would have made conversation difficult.
During his CB conversation with Agent Bowman while driving the 18-wheeler, McClane says, "If anything happens to me, send in the Calvary." Calvary is the Latin term for Golgotha, the Jerusalem hill on which criminals such as Jesus Christ were crucified. What Bruce Willis obviously meant to say was "send in the cavalry," the common historically correct term for sending fast-moving troops to the rescue. This error appears on the DVD theatrical version, but the unrated version gets it right.
When Gabriel calls to the F35 overhead he identifies it as AV Eighty-One. Real air traffic control or military command would have called it Alpha Victor Eight One, using the proper phonetics for radio communication.
Farrell refers to Mai as Gabriel's "girlfriend". Although it might have been an assumption or an offhanded remark, he had no way of knowing that the two were intimate. He did not see their kiss and never even saw them together.
Around 1:51:30 in the movie, we see a frontal shot of the semi ramming into the rear end of an older model BMW 7 Series, with an older model 5 Series in front. The camera then switches to the front and the vehicle shown being hit is an older model Mercedes Benz sedan (The same one used in a scene just a few minutes before. The license plate of the Benz ends in a 9 for both scenes).
Before McClane starts fighting Mai, she tries to take her gun that is on the desk right beside the computer. In a previous shot, the gun can be clearly seen under a couple of cables. When she tries to reach for it, the cables are gone.
When the bad guy ("Rand") jumps from the helicopter (as McClain crashes the police care into) his headphones fall off as he hits the ground. But when the scene jumps back to him getting up from lying on the ground, Rand's headphones are magically (and mistakenly) back on.
In their first phone conversation, Gabriel tells McClane he knows him pretty well, as he's got all the info concerning him displayed, including all career records. Among the decorations received, we see he has been awarded a commendation in 1987 for the Nakatomi Tower incident in LA (referring to the events in "Die Hard"), and a citation for the swift resolution of the Chicago Airport Incident in 1990 (referring to those in "Die Hard 2"). This last record is wrong, as "Die Hard 2" was set in the Washington Dulles International Airport, and not in the Chicago Airport.
After the dump truck crashes into the cab next to McClane and Farrell, they flee on foot. In an overhead shot that follows, you can clearly see McClane getting out of the car, like he did when the scene began.
Near the end of the tunnel scene, McClane can be seen approaching a police cruiser which has a rooftop emergency light partially smashed up. Then, as he leaves the scene in the cruiser, the rooftop lights are completely in tact.
When the FBI are flying to the rescue at the end of the movie, they clearly state they are fifteen minutes out and then the camera pans to a shot of them with dockyards in the background. Firstly they are heading to the dockyards and secondly when we return to them later they are still flying over the same dockyards in the same direction.
When McClane and Farrell are in the BMW the BMW Assist feature turns on. This function would be impossible since the service relies on a cellphone link and the cell systems were previously disabled by Gabriel.
When Mai gets up again to fight McClane, McClane uses the nearby black monitor to attack her, which she blocks and tosses away. After Mai throws McClane out of the window, and goes for Farrell, the monitor can be seen back in its original position.
Rand leaves Gabriel to go look for McClane and kill him. Later we see Rand finding McClane in the cooling room. But in between these two scenes we see Gabriel talking to McClane on the radio and slapping his daughter, and Rand is in the background, leaning against a wall. This editing mistake means Rand leaves to go look for McClane, comes back to Gabriel and waits, then goes to look for McClane again.
After the fight scene between John and Mai right before she kicks him out the window, her face is shown bruised with specs of blood on it and her hair was undone from the fight but after she kicks him through the glass, her face is shown again cleaned up without any specs of blood and her hair is neatly tied up in the back from when she originally fought him. As she approaches Matt, her face is back to being bruised with specs of blood on it and her hair is undone and out of the pin again.
An ambulance begins to drive away down the street, followed by a police car. When you first see the ambulance, it has a red, white and blue stripe down the side. There is a cutaway, and when we return to the ambulance a second later, the stripe is now yellow.
After they have run over the fire hydrant, the car is visibly wet. It remains wet in close-up scenes, however, when in the scenes that are shot from a further distance, the car is completely dry. When the shot is zoomed in, the car is once again wet. This happens over several frames.
The two cuts on the back of John's head are inconsistent. Sometimes they are longer, shorter, horizontal or slightly vertical. Sometimes they are also more to the back of his head and end up switching slightly to the side.
When John answers Gabriel's phone call for Mai at the gas line facility, Matt secretly captures an image of Gabriel by remote controlling Gabriel's web cam. When he sends the screen capture to Bowman minutes later, the image's cropping has changed: Originally the image doesn't show Gabriel's entire head and hair, later it does.
(at around 7 mins) When Farrell is on his computer and the camera changes angle, you can see a completed Instant Message from Warlock, but the next scene reveals the Instant Message taking place with the exact same text.
In the truck, when Gabriel begins the download of files from the data facility (he tells the computer operator to "wait for it" when the download doesn't immediately start) all of the inhabitants of the truck are swaying, and the truck gives all appearance of being in motion. Moments later, Gabriel is outside the truck which is still parked up at their HQ, the truck doesn't begin moving for another few minutes.
In the elevator shaft, when the guy gets hit by Matt and falls onto the back of the SUV and drops his weapon into the SUV, the steering wheel is missing, just after John drove drove it into the shaft in the prior scene.
In Die Hard 3, John McClane was shown with a NYC Lieutenant's shield. In this movie, he has a Detective shield. A Lieutenant in the NYPD always has his shield, regardless if acting as a Detective, so it appears as if McClane was demoted for Die Hard 4.
In the tunnel scene, McClane and Matt went to the cement post to avoid being hit. The post was hit by a truck, the cement cracked so that the iron bars could be seen and McClane and Matt sat down due to the impact. On the continuing shot, no crack whatsoever could be seen on the very same cement post.
McClane's police service record accounts for every year of service from 1977 to date except for the period from 1995 to 2001, which is strange considering the fact that McClane received a commendation for 20 years of service in 1997 and a police star in 1999, as reflected on the same police service record.
When McClane and Farrell first walk into the police station, Farrell's ear is dripping with blood and down his neck, when they walk out, his ear is completely clean. When they jump to the next scene, the blood has reappeared.
In the beginning, when John and Matt get into John's car, you can see John reverse down the street and turn suddenly. His car is facing two walls when you see the man punch the window and grab him. He puts the car in gear and without turning starts going down the street.
When McClane and Farrell are being taken from the FBI to DHS, the two cars are directed onto a closed and deserted street (i.e. with no other traffic). However, a shot from the lead car (when the driver is on the radio to Agent Johnson) shows traffic moving outside the window.
There is no Middleton, WV. Also, when Matt and McClane watch the power go out from the power station, the view that is shown is not a view of any city in West Virginia. No cities in the state are that big or that flat. (The "Welcome" sign, however, is completely accurate as of 2007.)
When the fighter jet is chasing the truck, McClane is driving on West Imperial Hwy below Highway 105 in El Segundo, CA just south of LAX (nowhere near DC). In fact, the stretch of road is made to look longer because the camera flips the scene horizontally several times (the truck at some points may appear to be driving on the left hand side of the road).
When McClane highjacks the 18-wheeler and is supposedly driving through the streets of Woodlawn, MD. or nearby, you see direction signs point to Route 118 and to turn right to go to a Rental Car Return Lot "D". That actually is the corner of West Imperial and Aviation in Los Angeles, CA.
Los Angeles' Central Library building and Dorothy Chandler Pavilion are visible in the background of scenes set in Washington, D.C. Various other structures, including the metro, bus, and their stations, are clearly not Washington, D.C. Also, there is a height restriction on structures in D.C. but it is obvious that many buildings shown are taller than anything in the district.
In a series of moving aerial shots supposedly depicting areas on the east coast during a night-time power outage, there is a brief shot of downtown San Jose. This is either an error in using stock video of power outages, or an intentional nod to the city some call the Capital of Silicon Valley and the center of the computer industry.
While driving through D.C., McClane, Farrell, and Johnson turn onto 14th Street, shown as a narrow street that ends in a 'T' intersection and represented on the bad guys' screens as running East/West. In reality, 14th Street is much wider, runs North/South, and is continuous except at Walter Reed Medical Center, which is nowhere near where the car would be traveling through the city.
When taking Farrell to DHS, and throughout the effort to evade the gunfire from the helicopter, the events of the movie supposedly transpire in Washington, D.C. yet the shots of the street are clearly downtown Baltimore.
When McClane and Matt first arrive in DC they are shown traveling north on 12th St NW between Constitution and Pennsylvania Avenues. Moments later they are shown emerging from the 12th St tunnel, i.e., the intersection of 12th St NW and Constitution Ave northbound.
The F-35 Lightning II shown in the film uses its VTOL engine to hover and shoot at its target. The VTOL (Vertical Take Off and Landing) engine is purely for that; taking off and landing. Hovering takes an incredible amount of fuel, and can overheat the hover engine since its duty cycle is not 100%. Additionally, the difficulty in making the craft successfully hover would make it virtually impossible to also track and fire on a target. As such, pilots are never, ever trained in or participate in hovering attacks.
The IP address that is displayed when the Metropolitan Transportation Authority is being connected to remotely is 192.24.647.90. The third number is not possible within the rules of IPv4 addressing, as it is larger than an octet (8 bits/0-255) can represent. This was not done intentionally by the filmmakers to avoid giving out a valid IP address, because elsewhere in the movie internal network addresses are used (10.x.x.x, 172.16.x.x and 192.168.x.x), and a real address is also shown, 220.127.116.11.
The F-35's call sign is AV81. Under no circumstances is this a legitimate military call sign. As it is a USMC aircraft by the fact that it is a F-35B vice F-35C as said in the movie, it would either be some tactical call sign (word) followed by eight one or VMAV081 (pronounced: Marine Alpha Victor Zero Eight One). If it was a F-35C as said, it would be either some tactical call sign followed by eight one or VVAV081 (pronounced: Navy Alpha Victor Zero Eight One) and it would not be a VTOL variant.
The vehicles John and Farrell are traveling in when they are ambushed in Washington are marked "FBI Police". As they are vehicles used by the federal government, they should have US Government license plates, not Washington DC plates as shown.
There is no national power grid. The continental United States is divided into three main power grids: The Eastern Interconnect System, the Western Interconnect System, and the Texas Interconnect system, not eastern, western, and central as Farrell claims.
The BMW 5 series that is stolen has a security system (you can tell by the red light sticking out of the rear-view mirror) which means the car would have detected the smashed window and the motion of the people inside. As a result, the alarm would have sounded and the authorities been notified (due to the apparent existence of BMW assist feature in the car)
While the bad guys may have been able to identify the IP address that someone was using, the name of the user does not come up. The best they could do is identify the ISP. Moreover, Warlock would be smart enough to have Internet access under a different name, at least his mother's.
The "police radio" in McClane's NYPD car (and a few other official vehicles in the film) was actually a HAM radio. It was an ADI model AR-147 FM transceiver. It was tuned to 144.330 MHz which is an amateur radio frequency in the two meter band. Except for extraordinary emergencies, that band is not used for law enforcement communication.
In the scene where the BMW 5 series is broken into, the car makes a beeping sound when started. The sound that is emitted does not come from this particular model, rather the smaller, cheaper 3 series which relies on an independent buzzer. The more expensive 5 series makes a different sound due to the fact that the car gives all its indications via the car's on-board computer and color display (iDrive) and audible beeps and warnings via the sound system.
John McClane takes over a large truck equipped with a Uniden Bearcat brand Mk III Trunktracker, a popular vehicle-mount radio scanner. Radio scanners are solely for reception purposes only, and it is impossible to transmit a radio signal using such a device.
When John transmitted on his alleged "Police Radio", the squawks your hear at the beginning of his transmissions is MDC signaling. This is a Motorola product protected by multiple patents. Any amateur rig has never included MDC signaling.
When the pilot ejects from the F-35 jet, his parachute canopy takes several seconds to inflate and indeed, the chute is dramatically barely inflated just before the pilot hits the ground. Actually, the F-35 is equipped with the advanced Martin-Baker ejection seat which includes a parachute designed to fully inflate in one second or less, as pilots may need to eject from the aircraft at "zero altitude" (still on the ground) and still land safely.
When the government is hit by the first hacker attack, the monitors and screens go dark, implying full power outage. When power is restored, the monitors all revert straight back to displaying programs, rather than to a boot-up screen.
When Gabriel demands to trace Lucy, one can clearly see that they trace her to a specific spot. The only way to do this would be if her phone had GPS, which it does not. Moreover, Lucy was in a building, where GPS signals generally do not reach.
As the terrorists take over and shut down the DC area's information infrastructure, one screen shows the MTA (Maryland Transit Authority)'s logo with a map of the Washington, DC, Metro subway system. The WMATA, not the MTA, oversees the Metro.
The F-35 in the movie is referred to as the F-35 C, however it is the F-35 B that has hover capabilities. The F-35 C is the planned carrier variant, with no VTOL capabilities but better suited for carrier launches and landings.
The scene where all the gas is routed to where McClane and Farrell are makes the assumption that the gas would somehow ignite right as it arrived at the hub. An ignition source is needed as well as a breach in the gas line. Even if the gas did ignite, that would cause an even bigger problem because the gas would continue to flow and burn via the breach in the line until it was shut off. Even after the explosion that destroyed the hub McClane and Farrell would have been vaporized from the intense heat of the ignited escaping gas under pressure.
When IP addressed are traced to reveal a person's name, the IPs displayed for these traces (172.16.55.103 and 10.252.27.112) both belong to IANA private network IPv4 address space reservations. Realistically, IP addresses in this range do not exist on the Internet, as they are reserved for internal network use only. An attacker would need to be on the same local-area network as the victim for a reserved address to be returned in a trace, but this scenario would obviate the usefulness of such a trace in determining the geographical location of the victim. This may have been done intentionally by the filmmakers to avoid giving out IP addresses that could be reached via the Internet.
All the way through the scene with the F35 attacking the 18-wheeler, none of the other cars in shot are moving unless they are run into by the truck. However, the cars aren't moving because they have been abandoned.
If there are three power substations for the West, Mid-West, and East, and you have to physically be there to shut them down, then there should be two more crews out there that McClane didn't stop. However, Gabriel's henchmen explicitly say that they shut down the West and Central grids, and they were waiting on Mai's, prompting Gabriel to radio Mai, leading to his exchange with McClane.
In the scene where the antagonists trace Lucy's cell phone to call her, the display depicts her SIM card number as "270A486FC78". In reality, none of the serial numbers used to uniquely identify a SIM card to a cell network are alphanumeric; they contain numerical digits only. This may have been done intentionally by the filmmakers to avoid inadvertently giving actual SIM card codes.
When Thomas Gabriel pulls up McClane's police record, the record displays McClane's social security number as only containing 8 digits. (This may have been done intentionally by the filmmakers to avoid the possibility of giving out someone's real Social Security Number.)
After McClane shoots the driver of the truck, it sounds like the truck is shifting a gear up. Since the driver has been shot, there would be no one to shift gears. Furthermore, immediately after McClane gets in, it's shifting up again, although McClane is not yet driving the truck.
In a still-shot of McClane and Farrell driving along on the highway, it is evident that the shot was sped up to look as if they were going fast, and it is noticeable that their flashers were on as the car passes the camera (also note the long line of traffic behind the car).
When McClain grabs the cable that is hanging through the back glass of the SUV in the elevator shaft you can clearly see that the end of the cable is about 12 inches below his hand, but when the SUV falls McClain has about 10 feet of cable under him.
After McClane jumps out of the police car in the tunnel, the car's engine can be heard revving and accelerating before jumping into the helicopter, even though there is no one in the car pressing on the gas pedal.
In the scene where they end up in the lift shaft with the SUV, there is no actual lift car in the shaft despite the cables for it being shown and had there been one it would have been damaged during the scene, either falling on them from above or falling away below.
When McClane is escorting Farrel from FBI to DHS when they are attacked by the helicopter, McClane is seen turning the wheel multiple times in the same direction. Not only is this impossible but when you look out of the front window the car is going straight.
The goof items below may give away important plot points.
When Gabriel deletes McClane's 401k and offers to clear his debts in return for shooting Matthew, the audio is clearly unsynchronized from lip movement when McClane responds and calls Gabriel a jerkoff. This remark was obviously dubbed over something more profane when the film was edited down.
During the elevator scene when one of Mia's henchmen shoots through the rear window of the SUV we can see thousands of glass shards on and splintered on the back of the rear seat. However, when McClane proceeds to climbing out the rear after it was safe, the backs of the rear seats were perfectly clean, without a single piece of glass.
When Matt Farrell and Lucy McClane are tied up in the control room near the end of the film, a lamp is visible in the background during close-up shots of Matt. This lamp is ON during close-up shots, but then turns OFF whenever there is a wide shot of Matt.
In the final scene where John is talking to Matt in the back of the ambulance, when they cut to where John closes the ambulance doors - before the cut the paramedic is about head height with Matt without the stethoscope in his ears but after, he's about stomach height with the stethoscope in his ears.
At the end when Gabriel has McClane against him saying what to put on his tombstone, when McClane pulls the trigger, the bullet goes through him and would hit Gabriel on the right side of his body by their positioning, but when they pan over to him on the ground dead, he has been shot on the left side (hence him dying so quickly, most likely from a bullet wound to the heart).
At the end of the movie, the warehouse that Gabriel goes to is near Baltimore, yet when the military takes control of the warehouse, a DC firefighter is seen entering the roped-off area. DC firefighters would not have jurisdiction in or around Baltimore, and therefore would have no reason to be there, unless to aid the Baltimore firefighters (and since there was no fire, no need for them).
Based on the location of the gunshot to McClane's shoulder, it is very unlikely that he would be able to move his arm because the bullet would probably have severed part or all of the brachial plexus (which is made up of the nerves going into the arm).
During the tunnel scene, after the bad guys turn off the lights, not a single one of the cars have daytime running lights on, nor do any of those sporting automatic systems have their lights turn on. Furthermore, despite the fact that we see dozens of cars enter the tunnel from both ends and smash into each other, when McClane commandeers a car he is able to easily accelerate through the tunnel exit without having any close encounters with either cars or debris.
Apparently, Gabriel's semi-auto pistol, at the end of the movie, does not like to eject spent ammo casings. In the scene where he shoots Matt in the leg and the subsequent two shots in the air, no sounds of brass hitting the ground, or anything is heard.
When Lucy is being led to the hazmat truck, shortly before John rescues her, she is seen being led by one of the bad guys, with a black cable tie (plastic strap) binding her wrists like handcuffs. This strap is clearly so loose that she could just slip her hands out, and she must actually be stopping it from just falling off.
When McClane has just slid down the broken highway after jumping off the plane, the burning car on the right side of the screen clearly has no back seat; the frame is visible and the inside of the car has been stripped completely bare.