Other mistake: The tail that Rogue grows appears out of thin air as if it were magic. Given that she's going through an organic transformation, the tail should have formed gradually out of her coccyx. (00:15:55)
Other mistake: After Rogue absorbs Wolverine's healing powers and purges the transformation spores from her system, she reverts back into human form including losing the tail that she grew. Given that the tail protruded from her backside, there should have been a hole in the back of her pants afterwards, yet there is none. (00:16:40)
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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