Continuity mistake: When Magneto is telling Wolverine that Xavier wouldn't approve of his commando raid, his neck area is flesh colored, when it was previously shown to be purple because of his costume. (00:16:45)
Continuity mistake: When the X-Men are following Magneto to see Xavier, Cyclops is on the far left and Iceman is standing next to him. Once Magneto has opened a doorway to the room Xavier is in, Cyclops and Iceman have swapped places. (00:17:10)
Continuity mistake: When Magneto uses his powers to create a hole in the metal wall, the edges of the wall surrounding the hole are smooth. When the shot changes, the edges suddenly look crumpled. (00:17:16)
Continuity mistake: When Magneto is standing at the foot of Xavier's bed, the bed frame and drapes are present or missing depending on the shot. (00:17:44 - 00:18:20)
Factual error: When the X-Men are surfacing after crashing their jet into the dam, Shadowcat is shown phasing through the jet and pulling Wolverine and Beast through with her. Since Wolverine's bones are coated with a heavy metal, he wouldn't be able to float to the surface. He would sink instead. (00:14:57)
Revealing mistake: When Cyclops asks Emma Frost what is happening when Shadow King is transferring his consciousness from Storm's mind into Wolverine's, you can see Cyclops and Emma have white outlines drawn around them, indicating they were drawn separately and composited into the shot. (00:19:06)
Continuity mistake: When Cyclops tries to shoot an optic blast at Shadow King's astral form, his right hand is bare. When Shadow King attempts to possess Cyclops, he is suddenly wearing a glove on his right hand. Both of his hands are then bare when he is helping Storm to her feet. (00:19:38)
Other mistake: When Magma is running from the MRD at the beginning, her feet are so hot that she leaves magma-filled footprints in the ground, but somehow her shoes remain intact. (00:01:54 - 00:02:34)
Other mistake: When Wolverine puts on his motorcycle helmet, the visor is down. When he pulls out of mansion grounds and stops to sniff Gambit's scent, the visor raises without him touching it. (00:08:27)
Continuity mistake: When Wolverine knocks out the security guard, he collapses in front of the parking arm. When Gambit and Wolverine are shown looking up at the water tower, the parking arm is just behind them, and the guard is no longer there. (00:14:17 - 00:14:47)
Continuity mistake: When Gambit is fighting the guards, he knocks out three of them. When Wolverine begins walking away, there are now four guards unconscious on the floor. (00:15:26)
Continuity mistake: When Wolverine is taking cover from the Sentinel Prowler, there is a blast mark in the pillar by his head. After Gambit asks Wolverine to give him back the collar, the blast mark has disappeared. (00:20:55)
Continuity mistake: When Wolverine returns home at the end, the counter where Forge is standing is across from the end of the table where Shadowcat and Iceman are sitting. In the final shot before the credits roll, Forge and the counter are now behind Shadowcat. (00:21:58)
