Continuity mistake: When the camera pans around the team after Lilandra saves Xavier, Storm's communicators are colored white whereas they are normally red, and Rogue's gloves are missing below the wrist. (00:18:50)
Continuity mistake: When Jean Grey is stating how Magneto's powers intensified her own, the left side of her costume around her abdomen is colored yellow whereas it is usually blue (the right side remains blue in this shot). (00:13:30)
Continuity mistake: When Magneto is saying "You are the next step in man's evolution," the lower half of Sunfire's mask is flesh-colored. (00:11:55)
Audio problem: When Magneto is saying "I have heard your cries for justice and I now answer that call," his mouth is not moving. (00:11:45)
Continuity mistake: When Trish Tilby is giving the news report, she is first shown to be in front of a gray news van. When the shot changes and for the rest of the report, she is standing in front of a blue screen. (00:05:30 - 00:06:45)
Continuity mistake: When Cyclops, Wolverine and Gambit are watching Morph giving a statement on the news while masquerading as Xavier, Cyclops' hair looks like a bowl-cut rather than the usual semi-shaggy look he sports. (00:06:20)
Continuity mistake: When Moira is asking the X-Men how they intend on contacting Lilandra, Jean Grey's face is colored yellow. (00:05:10)
Answer: Chris Potter, the original Gambit voice actor, did indeed quit the role in the 4th season. His last episode was The Phalanx Covenant Part 1 so it seems reasonable that Fox would limit the use of the character even though it was recast. It doesn't appear that Potter left the role due to animosity, he stated in an interview that he wished to play Gambit in the first live action X-Men film.
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