Factual error: When the US & Soviet navies attack the mutants on the beach they fire a large volley of surface to surface missiles. This is supposed to be 1962, the Cuban Missile Crisis, and ship launched surface to surface missiles had only just been introduced and weren't very common. But what makes this a technical error is that in the barrage we see RGM-84 Harpoon anti-ship missiles, introduced in 1977, and RGM-109 Tomahawk missiles (could be anti-ship or land attack) developed in the 70s and first entering service in 1983.MegaZone
Factual error: A Westland Bell 47G helicopter with the a registration of G-CHOP is seen to land at the Russian army camp/military headquarters when Charles, Magneto and the X-Men are approaching. The registration denotes it is a British aircraft, so unlikely to be in the middle of Russia, and this particular model was built in 1966 - four years after the Cuban missile crisisrwbthatisme
Continuity mistake: In this movie, Emma Frost is seen as an adult woman [roughly around the same age as Professor X and Magneto]. But the character is also in X-Men Origins: Wolverine, set years later when Professor X and Magneto are much older, but in that movie she's younger than she is in this one. Although in Origins she is Kayla Silverfox's sister and her surname is never heard - the character was advertised and created as Emma Frost.Sprinkle!
Factual error: When sitting in Xaviers mansion there are cushions on the sofas made from a Sanderson fabric, Dandelion Clocks, this fabric was designed in 2009 but the film is set in 1960.
Continuity mistake: When Banshee is diving into the water, his "wings" are still attached. The shot angle changes, and his wings have disappeared before hitting the water. (01:39:20)
Other mistake: Near the end of the film, Magneto finally kills Shaw by pushing a coin through his brain. The blood on the coin is already dry when it hits the ground, even though only seconds have passed, and since we're shown blood leaking from the entry wound later, we know that it wasn't dry to begin with.
Factual error: Miniskirts weren't in fashion until at least 1965-66, and the high rise hemlines worn by many female characters weren't around until '68 or '69.
Continuity mistake: Before Shaw takes the grenade from Hendry, the latter one has his finger in the pin, and has it half pulled out by then. Look closely at Hendry's hand: he is still holding the pin, while Shaw takes the rest of the grenade, but in the next shot, Shaw pulls it out again. (00:28:10)Friso94
Factual error: The Cuban Missile Crisis was in 1962. Rossiya Hotel (shown in the background of the Red Square overview) was built 1964-1967. (01:10:05)
Factual error: During the bar scene in Argentina, Magneto uses a dagger he took from one of the former SS Soldiers. It appears to be a Reichsarbeitsdienst dagger with the inscription "Blut und Ehre." This is incorrect as the inscription should read "Arbeit Adelt." "Blut und Ehre" was inscribed on Hitler youth knives as that was their motto.maximus92
Factual error: When Erik pulls the bullet out of Xavier's back, the bullet should be covered in blood, but it is completely dry.
Factual error: When the US government deliberates about blocking access to Cuba, they request the 7th fleet to be dispatched for the blockade. The 7th fleet is on the Pacific Ocean, not on the Atlantic. (01:47:00 - 01:48:00)
Factual error: There is a pinball machine in the lounge area of the CIA facility where the young mutants gather. The pinball machine's name is "Fun Land", it is a 1 player (1 at a time) machine made by D. Gottlieb and Company in 1968, and did not exist in the film's 1962 timeframe.
Continuity mistake: The bartender points a gun at Erik, and his finger is inside the trigger guard. When Erik pushes the trigger using his superpower, suddenly the trigger guard is free of the finger.This is intentional, intended to illustrate the fact the Erik pushes the trigger, rather than the bartender pulling it. (00:24:40)Uri Raz
Character mistake: When trying to teach Banshee to fly, he is told to make his sound waves super sonic. Sound waves cannot be super sonic. Sound can only travel at the speed of sound, it always does. I guess they were trying to tell him to use a very high frequency, but the speed would still be the speed of sound.zubarsky
Revealing mistake: When Xavier saves Erik from drowning, the two have an exchange of words while floating at the water's surface. During these shots the water is churning violently around them but the two look stationary, indicating they are standing on a solid platform.
Continuity mistake: When Erik is first attempting to lift the submarine, he'd using his left hand. In subsequent scenes, specifically when Riptide turns into heavy wind to break Erik's grasp, he's now using his right hand.