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)
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)
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)
