The Phalanx Covenant: Part 1 - S5-E1
Continuity mistake: When Sabretooth is terrorizing the police and civilians, it is broad daylight outside. When Beast and Jubilee are shown approaching the scene in the Blackbird just before dispersing tranquilizing gas, it is twilight. (00:01:00 - 00:01:50)
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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