Continuity mistake: When Storm tells Gambit to put the discount placard back, he sets it in front of the clerk's computer. When the bellhop comes to get everyone's bags, the placard has disappeared. (00:13:24)
Continuity mistake: When Storm, Jubilee, and Gambit are checking into their bungalow, the desk clerk has a rose on his jacket that is missing in a couple of shots. (00:13:10 - 00:13:51)
Continuity mistake: When the walls begin closing in on the X-Men in the Danger Room, the blue center of Jean Grey's outfit is incorrectly colored the same light-orange color as most of her outfit. (00:03:12)
Continuity mistake: When Rogue is thrown into the wall by Storm's wind, the green side of her uniform is incorrectly colored yellow. (00:03:52)
Continuity mistake: When Gambit is avoiding the electrified coils in the Danger Room, his normally black and red eyes are colored like a normal person and his gloves are entirely fingerless whereas they are usually only fingerless for the thumb, index and pinkie fingers. (00:02:15)
Continuity mistake: When Jean is walking out of Wolverine's room, part of her dress around her abdomen briefly changes to a lighter shade of pink. (00:04:57)
Continuity mistake: When Jean is first shown in her dress, it is a solid pink color. When she is walking down the sidewalk on her date with Cyclops, the midsection of her dress is now a lighter shade of pink than the rest. (00:04:34 - 00:05:18)
Continuity mistake: When Jean Grey is first shown standing in Wolverine's doorway, her arm is resting on the door with her elbow level with her shoulder. When the shot changes, her elbow is now level with her breasts. (00:04:34)
Revealing mistake: When Gambit and Wolverine are pinned to the wall by Tar Baby, Gambit's face somehow gets between the tar and his right shoulder when he is saying "Sticky situation, mon ami." (00:12:01)
Continuity mistake: When Storm is blasting down the door to the small room Jean is captive in, there is a small vent cover to the left of the door. When the shot changes, the vent cover disappears, and then reappears in the next shot. (00:12:33)
Continuity mistake: When Rogue is flying Gambit back to the mansion, the green sides of her uniform above her belt are incorrectly colored yellow, and Gambit's neck is bare, when it should be colored black because of his headgear. (00:16:14)
Continuity mistake: When Storm is offering the Morlocks sanctuary at the mansion, several of the Morlocks that were standing dozens of feet behind Storm in a previous shot are now standing in front of her. They are then behind Storm again when she is helping Callisto to her feet. (00:18:58 - 00:19:45)
Continuity mistake: The picture of Jean and Cyclops Wolverine has framed shows them against a yellow-orange background, and Cyclops' sunglasses are red. When the picture is shown again at the end of the episode, the background is now white and Cyclops' sunglasses are gray. (00:08:14 - 00:20:44)
Continuity mistake: When Wolverine finds the unconscious Cyclops, Cyclops' sleeve is rolled all the way down. A couple of shots later, the sleeve is now rolled halfway up. (00:16:42)
Continuity mistake: After Jean and Cyclops first kiss after she tells him to relax a little, his left arm is around her shoulder and it suddenly jump cuts to his side with his hand in his pocket. (00:05:37)
Continuity mistake: When Leech telekinetically splits up the mob, on his left are a man with a light blue shirt, followed by a man with an orange shirt, and man with a light blue shirt behind him. On his right are a man with a green jacket and yellow shirt, a man with an orange jacket and pink shirt behind him, and lastly, a man with a blue jacket and yellow shirt. When the shot changes, the men have not only swapped sides, but now it is two men in light blue shirts in front of the man in the orange shirt, and the man with the orange jacket and pink shirt is now just wearing an orange shirt, and he is standing in front of the man with the green jacket and yellow shirt, and the man with the blue jacket and yellow shirt is in front of him. (00:06:05)
Continuity mistake: When Wolverine punches his lefthand claws into the wall, it is at bottom of a slab of concrete, and to the left of where four slabs intersect. When the shot changes, the puncture is now closer to the middle-right area of a slab. (00:13:16)
Continuity mistake: When Jean is saying "Where am I? What's happening?", she has a lock of hair draped over her left shoulder that suddenly turns a darker shade of red. (00:13:26)
Continuity mistake: When Wolverine is saying "Cyke has his problems, but he don't smell like a Morlock," Gambit's bare neck is visible, when it should be colored black because of his headgear. (00:14:11)
Continuity mistake: When Sabretooth tells Jubilee that her powers are useless if she can't use her hands, the glove on her left hand turns from yellow to brown multiple times. (00:15:50)
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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