The frequent delays caused by COVID-19 ballooned the budget to $291 million, making it the most expensive Mission: Impossible film (surpassing Fallout, $178 million), the most expensive film of Tom Cruise's career (again surpassing Fallout), and the most expensive film ever produced by Paramount (surpassing Transformers: The Last Knight (2017), $217 million). The insurance company Chubb originally gave Paramount only ?4.4 million (about $5.4 million) for the delays, arguing that the cast and crew could still fulfill their duties to the production despite being infected with COVID-19. Paramount sued Chubb in 2021, and the two companies settled in 2022. In 2023, Chubb gave Paramount a ?57 million (about $71 million) payout for the COVID-caused delays, reducing the film's budget to about $220 million, which still makes it the most expensive film for Cruise, Paramount, and the franchise.

When Ethan and Grace meet for the first time at the airport, Tom Cruise insisted on performing the magic trick with the two halves of the key practically. Despite numerous failed takes, the desired effect was ultimately achieved in-camera with little to no visual effects.

While filming in Italy, twelve people on the set tested positive for COVID-19. As a result, when filming resumed in the UK, Tom Cruise personally paid ?500,000 for an old cruise ship for the cast and crew to isolate on.

When the production wrapped, Pom Klementieff was treated to a skydiving experience by Tom Cruise who dived with her for the initiation jumps.

Director Christopher McQuarrie found Pom Klementieff to be such a self-propelled force of nature on set, she was nicknamed "Pom Cruise" for her gymnastic skills.

Continuity

Grace crawls over the coals on the train. For the rest of the movie, her shirt is completely unmarked with any coal stains.

During the chase scene in the small yellow Fiat, Ethan tells Grace "left left left" to make a left. Grace makes the left and audience see a black car parked on the right side of the street which Grace barely misses. Seconds later, Paris, who is chasing Ethan and Grace, makes the same turn but now the black car is gone.

When Grace (as The White Widow) slides the two halves of the key across the table to Kitteridge on the train, her hands and nails are clearly visible - her nails are cut quite short, with shimmery polish. A scene later, when Grace has removed her mask and puts her hands up, her nails can be seen extending beyond her fingertips.

When Ethan enters the train with a parachute he breaks the window but in the next frame there are no glass pieces.

At the beginning of the "The Austrian Alps" sequence, the number plate on Benji's BMW is Swiss. At the end, when he picks Ethan up, the plate is German.



Factual errors

When Grace (masked as the White Widow) is receiving $100m worth of cryptocurrency from Kittridge, the screen says "decrypting blockchain." Transferring cryptocurrency simply requires sending tokens from one wallet address to another, a transaction that is written in a blockchain. It does not involve encryption or decryption of a blockchain. In addition, the empty entry field is marked "IBAN" which would not be used in a crypto transaction.

The Orient Express uses electric and diesel locomotives provided by the local railroad, and does not use coal.

The super stealth submarine at the start of the film was continually transmitting active sonar pings, which would immediately give its position away to every ship and underwater sensor within several miles.

Would be impossible to uncouple the engine from the coaches while the engine is fully pulling the train.

The Orient Express does not travel from Venice to Innsbruck. The current Orient travels from Paris to Vienna via Munich. It did run Paris to Istanbul via Venice from 1919-1939 then again from 1945 till 1977. That?s the train Agatha Christie wrote about.



Incorrectly regarded as goofs

Steam trains, especially moving at high speeds, need to be continuously provided with fuel, in this case coal. With the engineers killed and the controls opened all the way, the locomotive would have gradually slowed down and come to a halt as the pressure in the boiler dropped. That train would never have reached the bridge for that distance with no coal provided. Since the early 1900s, when firebox coal consumption exceeded the efforts of two men, the trains have used mechanical stokers. The coal would continue feeding without one missing coal shoveler.

When the yellow Fiat rolls down the stone steps and lands upright there are no dents or scratches to the car. However, the car is clearly highly modified ( palm reader, self-driving, much higher power ) compared to the original ; so it may well also have a much stronger roof.

Obvious gas explosions at the NSA and yet no security or phone call for 10 min. Top-secret NSA unexplained (they didn't know it was gas) explosions required checking before emergency people rushing in.

Denlinger says that the biggest problem in security is the "human factor" yet he set up a massive room full of humans reading and manually copying top-secret records. However, the massive amount of records that needed to be copied could only be done by hundreds of people. Given the stakes involved, it would seem to be a reasonable and even necessary risk to take.

Analog signals are much easier to intercept and corrupt than digital ones. If you can obtain and plant explosives then you're capable of intercepting and altering analog communications using wire-taps and off-the-shelf radio scanners/transmitters. A digital entity would have difficulty with the physical tasks of obtaining, planting and wire-tapping.



Revealing mistakes

Venice is a densely populated city and major tourist destination but is depicted as completely deserted other than the people directly involved in the film's events.

Hunt slams Paris' head against a block wall to knock her out of the alleyway fight. The following day on the train, Paris has no bruise, scratch or any mark at all on her face/head.

In the train fight sequence, the camera captures the train from the side with both Ethan and Gabriel standing at the top of the train, and the train is visibly running very slowly, whereas, at this time, the train is supposed to be running at full throttle, at a high speed.

No impact of bullets on the dead bodies for the mercenaries in the desert.

At the airport, when Briggs first makes contact with "Ethan", he is in the "B" terminal (sign on ceiling indicating gates B10-B12). Then he is directed to "E" terminal where there is another sighting of "Ethan". When Briggs gets to that guy though, the same sign for gates B10-B12 can be seen.



Miscellaneous

The train cars continue to fall over the end of the bridge, despite the fact that most of the cars weight is clearly on the bridge.



Audio/visual unsynchronized

When agents arrive at the police station in Rome, they are in a BMW 5 series g30 when they leave to chase Ethan car changed to a 5 series g30 facelift.

When Ethan Hunt met with India-Zulu-254 he said, "Welcome the IMF." That's a grammatical error. But the English subtitle shows the correct form: Welcome to the IMF.



Plot holes

Alana has blue eyes. When Grace put mask and become Alana, she had brown eyes. Alana' s right hand man didn't notice and the IMF head man too. They looked at her face more than 5 minutes. Especially Alana's blue eyes are so different that is impossible her right hand man would not miss.