Beyond Good and Evil: Part 4 - S4-E11
Continuity mistake: The end of the episode shows Xavier standing with no assistance. The only time in the series that the use of his legs were restored were a side effect of him losing his powers. He has his powers in this scene, so there's not really any reason for him to suddenly have the use of his legs back. (00:19:15)
Beyond Good and Evil: Part 4 - S4-E11
Audio problem: After Bender reverts to his true form of Immortus, he laughs before disappearing. The laugh is oddly inaudible on the DVD. (00:18:50)
Beyond Good and Evil: Part 4 - S4-E11
Continuity mistake: The same time portal with the image of the neanderthal by the fire is erased by Apocalypse twice. (00:12:45)
Beyond Good and Evil: Part 4 - S4-E11
Other mistake: During the montage of people being erased from time, the exterior shot of the X-Mansion shows part of the mansion destroyed. The mansion is later shown to be destroyed by Graymalkin after the heroes defeat Apocalypse, but at this point in the episode there's no reason for the damage. (00:12:20)
Beyond Good and Evil: Part 4 - S4-E11
Revealing mistake: After the horsemen collect the orb from Apocalypse, a second "onion skin" head of Apocalypse appears. (00:11:45)
Beyond Good and Evil: Part 4 - S4-E11
Continuity mistake: When Mr. Sinister confronts Magneto and Mystique, he is by himself. In the next shot, the Nasty Boys are suddenly behind him. (00:09:15)
Beyond Good and Evil: Part 4 - S4-E11
Continuity mistake: When the X-Men are fleeing the pyramid, Gambit's normally-black pants are colored blue. (00:03:20)
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.
BaconIsMyBFF