Gaffes

(at around 2h 20 mins) Scott is in the van trying a jump start, we then cut away and he is seen in the background battling a flying monster.

After the Battle of New York in 2012, Captain America's uniform was very dirty and noticeably torn in several places (as seen in the first Les Avengers: le film (2012) film), but here he is shown to have a pristine uniform after the battle.

In the very beginning of the film, Clint is teaching his daughter to shoot a bow and arrow and she hit the bulls-eye. Then Clint's family disappears after the snap, Clint looks around and the arrow is gone from the target but in the next shot, the arrow is back in the target.

(at around 1h 21 mins) Tony Stark is shown dressed in a SHIELD outfit without gloves, but is wearing gloves when picking up the briefcase containing the Tesseract, walking towards the stair door, and getting flung by the Hulk, then is shown again without gloves while laying on his back.

(at around 1h 14 mins) In Les gardiens de la galaxie (2014), Gamora is searching for the orb and is not aware it is an Infinity Stone until The Collector tells her about 2/3 of the way through the film. In Avengers: Endgame, she says when we first see her that "Father has found an Infinity Stone" (referring to the orb on Morag). This scene takes place just before the beginning of the events in Guardians of the Galaxy, thus creating discontinuity between the 2 films.

As well as the other inconsistency of Thanos having given his only Infinity Stone within the staff he gave to Loki for free in the original The Avengers (2012). Despite of his Infinity War and Endgame portrayal being obsessed with having the stones. Not to mention facilitating for Loki to steal the cube which contained another Infinity Stone. And that Loki having 2 stones, one of which controlled an alien army would put Loki in a place where he would had easily over-powered Thanos.

The entrance to Camp Lehigh is right along the street Stan Lee drives his car on. NO military installation is ever located along a street, like a house or a store, for obvious security reasons.

Upon meeting Red Skull, Black Widow says she never knew her father's name. For a Russian, this is not possible. Russian naming system automatically adds a middle name referring to their father's first name, which literally means "son/daughter of...". Even if she was lied to about her real father, that's not the same of not knowing his name, it's literally included in her own full name.

(at around 45 mins) Tony Stark drives an Audi e-tron gt, which is a fully electric concept car. When he arrives at the Avengers headquarters a loud combustion engine race car sound is heard. However, electric vehicles are a risk to visually-impaired pedestrians, and many countries have legislation requiring them to make a noise; someone with Tony Stark's technical capability (and ego ) may well have added a noise-generator which mimics a powerful engine.

(at around 4 mins) Stark mentions that he and Nebula got the Benatar running for 48 hours after fixing the engines, but the ship was now dead in space. This does not mean the vessel would slow to a stop (as if on a planet) but would drift onwards until affected by external forces. While the scene showing the unpowered Benatar seem to show it immobile, it is perfectly reasonable to assume it is still moving, adrift in space. (Explaining the presence of gravity within the vessel is somewhat harder!)

Thanos thinks he solved overpopulation forever, then destroys the stones and retires. But he just cut population in half once, it can grow back in just a few generations.

Thanos presumptuously believed that everyone would be grateful that he "saved the universe", which is made clear when he tell the Avengers that they "should be grateful" that he murdered trillions. Perhaps he expected everyone to express their gratitude by cutting down on reproduction in order to maintain balance.

(at around 15 mins) As soon as they exit the hyperspace jump, we see Captain Marvel going down to the planet. Then the angle switches to Captain Marvel in front of the ship telling them that she is heading down to the planet for recon on Thanos. Incorrectly regarded as goof: Captain Marvel is only exiting the spacecraft to move in front of the cockpit, she does not go to the planet surface until after she tells them.

(at around 1h 28 mins) When Thanos magnifies the holographic reflection of Nebula it is not a mirror image.

However, in this particular shot, the camera is on the opposite side of the hologram from Thanos. Thanos would be looking at the holographic reflection of Nebula, which is a mirror image, but the camera is on the opposite side and would pick up the flipped image.

(at around 25 minutes) When Scott Lang is visiting the memorial looking at the names, the camera shows the stone he's looking at, the camera shows a frontal shot of Scott looking at it. The stone did not have his name anywhere near his eye line. But he spots his name and then the camera shows his name even though it wasn't in the shot of the stone before.

(at around 56 mins) After Barton stabs Akihiko with his sword, the camera pans out to reveal Black Widow watching. If one looks down at Akihiko, the actor (Hiroyuki Sanada) is visibly moving and breathing.

When Stark and Nebula are on the ship that is "dead in the water", since there is no power there should be no gravity (assuming the ship has artificial gravity capabilities). Yet they are walking/sitting as if there is gravity.

While on the military base, a large cargo/personnel truck is seen. The tires are incorrect for the period. Correct tires would have been the skinny tires with duals on the rear. Super singles are seen, which were not used until the A1 series (first rebuilds/overhaul) of the 1982 trucks.

In 1970 virtually no one in the US had heard of the Bee Gees, plus the Bee Gees definitely were not hippies.

When Captain America decide "to get a life", he returns to a home (presumably) in the 1940's with architectural shingles on the roof. That style of asphalt shingles wasn't introduced until the 1970's.

(at around 48 mins) When Hulk and Rocket visit New Asgard to see Thor, the vehicle they arrive in has a UK-style registration plate but New Asgard is Norway (rear registration plates in the UK are yellow, but white in Norway). However, the actual registration used (SN615PN) is not a valid UK registration as the current format is two letters, two numbers, three letters. Nor is it a valid Norwegian registration which uses the format two letters, five numbers.

In Avengers: la guerre de l'infini (2018), Tony is using nano-tech armor that instantly forms itself into the armor or weapon he needs at the moment based on his slightest whim, and then stores itself in his chest-piece (as he explains to Pepper). But in his first scene in this film, he has to reach inside a solid helmet to activate a button to make it record. Not only would such a button be useless when the helmet was on his head; the helmet shouldn't exist on the floor of Quill's ship. The recorder should have appeared out of the chest-piece the instant he thought about needing it.

When the Avengers travel back in time, each one has only enough Pym particles to return to the present time. This is the last of the particles. Professor Hulk promises The Ancient One that the Infinity Stones would be returned to their original time line. This could not be done without more Pym particles. Unless of course Banner was confident that Hank Pym would return and make more.

Also, Nebula would have had one particle after retrieving the power stone. Past Nebula returned with the Avengers and Thanos' ship returned later. Nebula was seen giving the Pym particle to Thanos. She could not have returned ahead of the ship without the particle.

2014 Nebula only has to steal 2024 Nebula's suit and use duplicated Pym particles to return ahead of the ship.

When Stark and Scott are in 2012 Avenger's time-line, they do not interfere with any of the events of the battle until the very end, where they try to steal the Tesseract. This means that Hulk going down the stairs and bursting through the door when he reaches ground was an event that happened in the original time-line. Stark would have certainly remembered that, but in the movie he is caught completely off guard by this event.

It is a major plot point that time travel is only possible with either the time stone, or with Pym particles plus an ant suit plus a quantum tunnel carefully programmed by Stark & Banner. Yet Thanos takes his entire gargantuan ship through to attack the compound as Hulk snaps his fingers; and Tony & Steve travel farther back without a tunnel. However, characters were returning back without a tunnel and had particles. About Thanos - directors have said hat Maw replicated particles that were taken from 2023 Nebula.

(at around 59 mins) Rhodes lists several time travel themed movies in which someone changes the past and thereby changes the future. However, he mentions four movies that go against his argument:

• He mentions Star Trek (2009), whose time travel theory is actually very similar to this movie. When Spock Prime traveled to the past, all the changes made did nothing to affect his own timeline, however he still sought to make sure that the newly created timeline remained somewhat similar to his own.

• He then mentions three - Terminator (1984), Quelque part dans le temps (1980), and Les excellentes Aventures de Bill et Ted (1989) - which follow the theory of the Feedback Loop or Predestination Paradox, which states that anything done by a time traveler to change the past ironically causes the future to unfold the way it has always done.

(at around 1h 12 mins) As Black Widow and Hawkeye are leaving Morag, Nebula is commenting on the coordinates for Vormir. During this line the side shot of her it appears that her right ear's make up is incomplete despite other shots surrounding these scenes showing her ear normally.

In Tony's recording after the final battle he states that if someone told him 10 years ago that we weren't alone in the universe he would find it difficult to believe. That math only works in the real world with the MCU movie release dates. In the movie it is established that the battle of New York from The Avengers (2012) happened in 2012. Avengers: Infinity War (2018) happened in 2018, and majority of Avengers: Endgame (2019) takes place 5 years later in 2023. This would make Tony's statement of "10 years ago" take place a year after the battle of New York where the Avengers fought an army of Chitauri aliens and Tony himself flew into space to destroy their ship.

In the discussion with Hulk about the nature of time, Rhodey lists several movies to back up his point that the past can be changed. However, two of those movies: "The Terminator" and "Somewhere in Time" argue against his point as they feature a "stable time loop", wherein the past actions of the time traveler lead directly to the circumstances which causes them to time travel.