The Phalanx Covenant: Part 2 - S5-E2
Continuity mistake: When Xavier is first shown in his containment bubble, he is shown with his hands resting at the center of his hover-chair with his left hand on top of the right. When the shot changes, his hands are suddenly separated and at the sides of his chair. (00:14:00)
The Phalanx Covenant: Part 2 - S5-E2
Continuity mistake: When Cameron Hodge says to Wolverine "The X-factor is ours," his left hand is on Wolverine's chin. In the very next shot, his hand is suddenly no longer on his chin. (00:13:45)
The Phalanx Covenant: Part 2 - S5-E2
Continuity mistake: When Cameron Hodge says "Wolverine gets a gold star," Wolverine's normally red belt is colored yellow. (00:13:40)
The Phalanx Covenant: Part 2 - S5-E2
Continuity mistake: When Cameron Hodge is duplicating Gambit's mutant power, his arm is yellow. When the shot changes, his arm (or at least his hand) is flesh-colored. (00:13:35)
The Phalanx Covenant: Part 2 - S5-E2
Continuity mistake: The Phalanx-infected Gambit goes from being yellow and black in one shot to having the appearance of his usual color scheme in the very next shot. (00:13:30)
The Phalanx Covenant: Part 2 - S5-E2
Continuity mistake: When the group is talking to Cameron Hodge's Phalanx facsimile, sometimes Forge is behind Beast on his left, Mr. Sinister is behind Forge on his left, and Warlock is behind Forge and Mr. Sinister. Other times Warlock is behind Beast on his left and Forge and Mr. Sinister are not in the shot. (00:10:45 - 00:12:45)
The Phalanx Covenant: Part 2 - S5-E2
Continuity mistake: When Magneto says "To do what?" he is wearing his purple gloves. When he is shown in closeup, he is not wearing any gloves, just a red long-sleeve shirt. (00:08:35)
The Phalanx Covenant: Part 2 - S5-E2
Continuity mistake: When Amelia says "The Earth is in danger from an alien infestation," Mr. Sinister's normally-blue boots are colored red. (00:08:35)
The Phalanx Covenant: Part 2 - S5-E2
Other mistake: When Mr. Sinister, Beast, Forge, Warlock and Amelia are walking towards Magneto, they walk in place for several strides. (00:08:30)
The Phalanx Covenant: Part 2 - S5-E2
Continuity mistake: After the Phalanx captures Banshee, the bubble he is encased in disappears when the shot changes. He also goes from being turned away from Moira to facing her direction. (00:07:40)
The Phalanx Covenant: Part 2 - S5-E2
Continuity mistake: The Phalanx-civilian that is dressed like a biker that attacked Beast and the others outside the restaurant in Milford Township, PA at the end of the previous episode is suddenly outside the Empire State Building at the very beginning of this episode. (00:02:00)
The Phalanx Covenant: Part 1 - S5-E1
Continuity mistake: When Mr. Sinister blasts the Phalanx-civilians, his gloves are red. A couple of shots later, his gloves are their usual blue. (00:17:50)
The Phalanx Covenant: Part 1 - S5-E1
Continuity mistake: When Beast says "And we waited until you arrived," his eyebrows keep changing from blue to black. (00:16:10)
The Phalanx Covenant: Part 1 - S5-E1
Continuity mistake: When Beast replays the video of Warlock's tissue sample assimilating the metal, the human and mutant tissue samples on the left have disappeared. (00:11:35 - 00:12:30)
The Phalanx Covenant: Part 1 - S5-E1
Continuity mistake: When Beast is trying to escape the Phalanx in Wolverine's jeep, he has to drive down a considerably long road just to reach the gates to the mansion. In all previous episodes, the road leading to the mansion is barely longer than a driveway. (00:08:35 - 00:09:10)
The Phalanx Covenant: Part 1 - S5-E1
Other mistake: As usual, Wolverine's jeep is missing its windshield. (00:08:25)
The Phalanx Covenant: Part 1 - S5-E1
Revealing mistake: When Beast lunges away from the Phalanx disguised as several people in hazmat suits, after he lands he glides across the grass. (00:08:15)
The Phalanx Covenant: Part 1 - S5-E1
Continuity mistake: When Beast is running from the Phalanx through the mansion's hallways, his trunks go from being Speedo-like to resembling basketball shorts. (00:06:50)
The Phalanx Covenant: Part 1 - S5-E1
Continuity mistake: When Wolverine lunges at Sabretooth, his normally-red belt is colored yellow. (00:04:55)
The Phalanx Covenant: Part 1 - S5-E1
Continuity mistake: When Wolverine confronts Sabretooth in his holding cell, Wolverine's face is colored yellow. (00:04:25)
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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