Continuity mistake: When Storm says to Wolverine "You know small spaces overwhelm me," you can see that her lightning bolt earrings are suddenly missing. (00:06:30)
Continuity mistake: The mini-sub that Storm docked onto the hull of the nuclear submarine disappears and reappears throughout the rest of the episode. (00:07:20 - 00:17:45)
Audio problem: When Wolverine says "In a toxic nuclear powder keg," his mouth is not moving. (00:08:10)
Other mistake: After Omega Red stabilizes the nuclear sub while it is moving, the military somehow has a live video feed from outside the sub despite the fact that they didn't send any other submarines out to monitor the mission. (00:09:00)
Continuity mistake: When Beast presses the button to listen in on Omega Red, Storm and Wolverine, Rogue's arm is flesh-colored whereas it should be green since she is wearing her uniform. (00:13:35)
Continuity mistake: When Omega Red is wrapping the metal around the Storm, the portion of the metal that is protruding from Omega Red's grasp alternates between being brown and white in the same shot. (00:16:30)
Revealing mistake: When Rogue is shown tearing off the first portion of the submarine's hull, her feet are missing. (00:17:55)
Continuity mistake: When Rogue and Beast are in the Blackbird hovering above Omega Red in the ocean, the sky varies from being midday to being twilight depending on the scene.
Continuity mistake: The red omega symbols on the back of Omega Red's hands disappear and reappear throughout the episode, and are even sometimes colored white.
Continuity mistake: The number of "rows" on the purple devices on Omega Red's face varies throughout the episode, sometimes even changing quantity in the same shot.
No Mutant Is an Island - S5-E4
Continuity mistake: The hedge wall-enclosed landscaped area in front of the mansion at the beginning of this episode is an open lawn with trees and bushes in all other episodes. (00:01:05)
No Mutant Is an Island - S5-E4
Continuity mistake: When the X-Men are sitting in a circle at the beginning, Cyclops' gloves are missing above the wrist. (00:01:10)
No Mutant Is an Island - S5-E4
Audio problem: When Professor X is saying "We all know the risks of being an X-Man," his face freezes with his mouth open mid-sentence. (00:01:30)
No Mutant Is an Island - S5-E4
Continuity mistake: When Jubilee starts crying, Gambit's normally-black pants are colored blue. (00:01:50)
No Mutant Is an Island - S5-E4
Continuity mistake: When Cyclops throws his uniform on the ground, it turns into a dark gray color and the yellow paraphernalia attached to it disappears. (00:03:40)
No Mutant Is an Island - S5-E4
Continuity mistake: The governor in this episode is referred to as both Governor Barker and Governor Barkley. (00:04:20 - 00:13:40)
No Mutant Is an Island - S5-E4
Audio problem: Governor Barker has the exact same voice as President Kelly. (00:04:20)
No Mutant Is an Island - S5-E4
Continuity mistake: When Cyclops first approaches the orphanage there is a tricycle on the porch near the edge of the steps. When Sarah comes out and greets him, the tricycle has disappeared. (00:04:35 - 00:05:10)
No Mutant Is an Island - S5-E4
Revealing mistake: When Sarah turns off the stove burner you can see that there is an outline of a knob that the animators either forgot to fill in or forgot to erase. (00:05:35)
No Mutant Is an Island - S5-E4
Character mistake: When Cyclops demonstrates his power to Rusty to show him that he's also a mutant, he shoots an optic blast at a building and blows a gigantic hole in its facade. While the building had the appearance of being condemned, Cyclops had no way of knowing whether there were squatters inside. He could have seriously injured or killed several people for all he knew. (00:07:35)
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