Other mistake: During the "Previously on X-Men..." segment before the show's intro, it shows the Juggernaut landing in the ocean and walking across the ocean floor after Gladiator had hurled him away. However, Juggernaut's fate was never actually shown after Gladiator threw him. He was only seen fading off into the distance.
Other mistake: When Corsair is running towards the Starjammers and Storm at the top of the Mayan structure, Lilandra can be seen among the group despite the fact that she was not in the episode before or after this moment. This was most likely supposed to instead be Jandra, the Shi'ar child that the Starjammers were trying to protect.
Plot hole: Magneto states that he went to Washington, DC to witness Senator Kelly's assassination. But Magneto had no way of knowing about the assassination plot. Mystique was the one who was attempting to assassinate Kelly, and Apocalypse was the one who carried out the order. At this point in the show, Magneto had not worked with either Mystique or Apocalypse, and it's highly doubtful that Mystique would leak the plot, since it was supposed to be covert.
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