The Phoenix Saga (2): The Dark Shroud - S3-E4
Other mistake: After the shuttle crashes into the Upper New York Bay, the X-Men escape the wreckage and swim up to the surface, with Wolverine being the first one to appear. Given that Wolverine's skeleton is coated with a heavy metal, not only should he not be the first one to surface, he should actually sink instead. (00:04:06)
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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