Continuity mistake: When Wolverine says to Sabretooth "Be careful what you ask for," his arms are yellow. (00:17:05)
Factual error: When Xavier is getting ready to get back into his hoverchair, you can see him raise himself to his knees, even though he is a paraplegic. (00:13:43)
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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