Continuity mistake: When Magneto lands the Golden Gate Bridge on the island, as it hits land it is still very light. When the Brotherhood start to walk toward the island, it cuts to a wide shot of them still walking on the bridge, and it's suddenly dark.
Factual error: Take a look at Google Earth - the section of the Golden Gate Bridge Magneto breaks off (about a mile - tower to tower plus a section each end) isn't anywhere near long enough to reach Alcatraz from anywhere on the mainland.
Continuity mistake: When Logan pulls out the two horns from his stomach, the camera shows two holes on the singlet as part as his wounds. In the following scenes, the holes of the t-shirt have recovered (I know Logan has healing ability, but not his clothes).
Other mistake: In the end credits, the job of paint foreman is misspelled as 'forman'. (01:41:50)
Trivia: Stan Lee makes a cameo appearance in the beginning of the movie when Jean is being recruited and showing off her powers. He is the man holding a hosepipe. (00:02:50)
Continuity mistake: When Angel is about to get the "cure" in the San Francisco skyscraper, you can see the reflection of San Francisco in the outside of the building - a huge hill with lots of buildings, and a large white tower at the very top. But when the camera switches to inside the building, looking outside, the view has suddenly changed to a view of the bay, and Alcatraz.
Continuity mistake: When Magneto and Charles Xavier are in Jean Grey's house (when she is older and making everything around her float in the air), watch the book shelf when it falls down. At least 25 books fall out of the top shelf and in the next few shots you see that the number of books fallen has minimized greatly. (00:45:00)
Continuity mistake: After Beast hits Magneto with the four needles, they change place.
Factual error: When Magneto has moved the Golden Gate Bridge, we see the President looking at a Satellite Image of Magneto's work. In this image, Alcatraz Island is bigger and closer to the shore than it is in real life.
Chosen answer: Both Wolverine and Mystique's mutations cause them to age slowly; effectively the normal human body deterioration is slowed for them, giving them a younger physical age than their actual chronological age. If that mutation was removed, then the factor that slowed their ageing would no longer function, but they wouldn't abruptly "catch up" with their actual age, they would simply possess a body at their current physical age which would age as a normal human after that point. As for the adamantium lacing Logan's bones, were his healing factor removed, he might well swiftly suffer extreme levels of toxic shock, which would likely prove fatal.
Tailkinker ★