Other mistake: In the version I watched, the subtitles that cover Sebastian Shaw's conversation with the Russian leader, had typos - the word 'missile' was spelled 'missle' on two, possibly three occasions and the word 'placed' was spelled 'places'.
Factual error: The CIA is operating within the United States, given that they're not allowed to do so. Everything the CIA did in the film really should have been done by the FBI.
Revealing mistake: In the submarine, when Emma goes to get ice for Shaw, Azazel's tail is missing when he helps pull the submarine's ladder down.
Revealing mistake: Watch when young Charles meets young Raven. Look closely and you can see the zipper on the child actress' costume.
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.
Other mistake: In the credits James McAvoy is listed as Charles Xavier (Age 24), then Laurence Belcher is listed as Charles Xavier (Age 12). The opening scene plays in 1944, while the rest of the movie plays in 1962 - a difference of 18 years, not 12.
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.
Chosen answer: He's not okay with it, but he knows that Erik's views appeal strongly to her. To all intents and purposes, she's already made her decision - to try to stop her would likely only lead to an argument, which is not how he'd want them to part. Plus there is the somewhat major side issue that Charles has just been shot, so it's not really the right time for a discussion on conflicting mutant philosophies.
Tailkinker ★