Days of Future Past: Part 1 - S1-E11
Continuity mistake: When Wolverine is saying "Thanks kid," to Bishop, his face briefly turns yellow. (00:06:21)
Audio problem: When Cyclops shoots an optic blast at War's feet during the battle at Stone Henge, the groan that War lets out is the same sound used whenever Wolverine's groans. (00:18:24)
Continuity mistake: When Rogue positions the platform that Mystique is shackled to upright, Mystique's feet are close to touching the floor. A couple of shots later, her feet are suddenly several inches higher. (00:14:08)
Continuity mistake: When Rogue is interrogating Mystique, she is standing in various places next to the platform depending on the shot. (00:13:45 - 00:14:08)
Continuity mistake: When Rogue is shackling Dr. Adler to the platform, she only applies the restraints to his arms and left foot, leaving the right foot unshackled. Moments after Adler reveals himself to Rogue to being Mystique, the right foot is now shackled as well. (00:13:31 - 00:14:08)
Continuity mistake: When the cameraman drops his camera, it lands on the ground and rests on a rock so that the lens is at a slanted angle. When the shot changes to the camera's point of view, it shows Apocalypse right side up, when he should be slanted to correspond with the camera. (00:10:14)
Continuity mistake: When Xavier, Jubilee, and Rogue are walking towards the end of the Blackbird's runway, their shadows on the wall show Rogue in front of Jubilee, but Jubilee is actually in front of Rogue. (00:10:51)
Continuity mistake: When Storm turns on the TV, the news reporter's microphone has a yellow 7 on a black circle. A couple of shots later, the black circle is now also yellow. (00:07:49)
Continuity mistake: When Xavier is briefing the X-Men about Apocalypse, Storm is on Xavier's left, and as the camera pans up and to the left, you can see no-one is around her. When the shot changes, Cyclops and Rogue are suddenly next to Storm. (00:10:21)
Continuity mistake: When Storm turns on the TV, much of the Eiffel Tower is in the background. A couple of shots later, the reporter is standing in front of a building that would obscure much of the Eiffel Tower, and is also suddenly standing next to a news van. (00:07:47)
Continuity mistake: When Mystique, disguised as Warren Worthington, first walks into the bar, the walls are purple. When she is saying "You don't have to be mutants," the walls are now red. When the shot changes, they are back to being purple, and a framed picture has appeared over her left shoulder. (00:04:18)
Continuity mistake: When Rogue, Cyclops, Jean Grey and Xavier are first shown in the bar, the glasses in front of Rogue and Cyclops contain green liquid. When Cyclops is consoling Rogue, the liquid is now blue. When the shot changes, the liquid in the glass in front of Rogue is now green again. (00:03:49 - 00:04:18)
Continuity mistake: When the Lady Gardener kills the rose, it droops down almost to the surface of the table. When the shot changes, it is now only drooping about midway down its vase. (00:03:56)
Continuity mistake: When Warren Worthington is strapped to the table, the arm and leg restraints are gold. After the table has been lowered, the restraints are now silver. (00:02:29 - 00:02:56)
Continuity mistake: When Gambit is saying "Scott and Jean pick one strange romantic hideaway," the encircled X on Rogue's right shoulder is entirely red, when the X and the circle around it should be black. (00:11:39)
Continuity mistake: The prosecutor for Beast's trial is wearing a pink suit. When the unruly civilian is being escorted out of the courtroom, in a wide shot, the prosecutor's suit is now white. (00:08:29 - 00:10:22)
Night of the Sentinels: Part 1 - S1-E1
Continuity mistake: When Jubilee's foster father is showing his wife what Jubilee did to the VCR, the glass door for the entertainment shelf goes all the way to the top. When the wife is asking her husband if he is sorry they took in Jubilee, the glass door is now only tall enough to cover the bottom and middle shelves. (00:02:17)
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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