Time Fugitives: Part 1 - S2-E7
Continuity mistake: When Beast is saying the plague could become dangerous for everyone, the breast pocket of his labcoat has disappeared. (00:13:17)
Time Fugitives: Part 1 - S2-E7
Continuity mistake: When Bishop is saying "You all must have died in the plague," the temporal band he wears on his right arm is missing. (00:12:48)
Time Fugitives: Part 1 - S2-E7
Continuity mistake: When Wolverine says "Again?" after Bishop says he was trying to save lives, the part of his mask next to his left cheek is colored yellow, when it should be black. (00:12:41)
Mojovision - S2-E11
Continuity mistake: When Jean is asking Mojo to leave Cyclops alone, some of the television screens that Cyclops just destroyed with his optic blasts are now intact. (00:06:28)
Mojovision - S2-E11
Audio problem: When Mojo is twirling around in a circle and saying "Am I standing?" to Major Domo, you can see his mouth is wide open for the entire line. (00:04:10)
Mojovision - S2-E11
Deliberate mistake: Some of the footage of the X-Men in action that Major Domo shows Mojo is clips from previous episodes, and even clips from the show's opening theme. (00:03:36 - 00:04:22)
Continuity mistake: When Wolverine is asking Graydon Creed if he looks familiar to him, his cuspids are very long and sharp. Later when Wolverine is sneering at Creed during his breakdown, you can see his cuspids are now flat and not as long. (00:17:29 - 00:19:36)
Time Fugitives: Part 1 - S2-E7
Continuity mistake: When Beast is giving Jubilee a checkup, his labcoat alternates between having no breast pocket and having one with a tongue depressor in it. (00:09:22)
Time Fugitives: Part 1 - S2-E7
Continuity mistake: When Jubilee approaches the manager of the electronics store, his name tag is the same yellow color as his shirt. A couple of shots later, it is now the same blue-gray color as his tie. (00:07:50)
Time Fugitives: Part 1 - S2-E7
Continuity mistake: In the second shot of Storm and Jubilee standing in front of the bookstore, there is either a light or a security camera on the ceiling two tiles in front of the gray sign that wasn't there in the first shot. (00:07:25)
Mojovision - S2-E11
Continuity mistake: When Major Domo answers Mojo's call, he is standing in a doorway. When the shot changes, he is already walking down the hallway alongside Mojo. (00:02:08)
Continuity mistake: When Wolverine cuts the doorknob off the door, you can see some of the door on the right side is still intact. When the shot changes, this part of the door is now completely missing. (00:16:55)
Continuity mistake: When Wolverine interrupts the two men playing poker, you can see there are only cards and chips on the table. When the shot changes, a mug has appeared next to the white man's left elbow. (00:16:28)
Time Fugitives: Part 2 - S2-E8
Continuity mistake: When Cyclops is asking Jean if she can locate Graydon Creed in the mansion, the two of them are standing in the same spot they were in the previous episode. However, in the previous episode, this occurred before they destroyed the fence and began to infiltrate the mansion grounds. In this episode, they have already infiltrated the mansion grounds before Cyclops asks Jean to locate Creed, so they couldn't be standing in the same place as before. (00:15:49 - 00:16:30)
Time Fugitives: Part 1 - S2-E7
Continuity mistake: When Bishop is shown returning to the year 2055, he looks out the window to a see a pristine looking city, and claims his intervention in the past to be a success. This is a contradiction to Bishop's return when it was originally shown at the end of the season 1 episode Days of Future Past: Part 2, in which he appeared in a run-down city and remarks that everything looks the same as it did when he left. (00:05:15)
Continuity mistake: When Rogue is visiting the comatose Carol Danvers in the hospital, Danvers' hair is parted down the middle and her bedsheets go all the way up to her neck. A couple of shots later, she has a lock of hair going down the middle of her forehead, and her sheets only go up to around her armpits. (00:20:17)
Continuity mistake: When Ms. Marvel first appears, her reflection is through the front window of the plane that Rogue is stealing. The lightning bolt design on her outfit and the red sash around her waist are not reversed in the reflection like they should be. (00:14:11)
Continuity mistake: In the flashback of Rogue's father disowning her, when he says he's ashamed to be seen with her, the number of stripes on the flag on his hat decreases from six to four in the same shot. (00:13:08)
Continuity mistake: When Cyclops, Wolverine and Gambit are evading the fire lion that Pyro created, Cyclops hops over a blue-green car. A couple of shots later, the car is now brown. (00:10:56)
Continuity mistake: When Mystique is telling Wolverine, Cyclops and Gambit that they stole something very important from her, the sclera of Gambit's eyes are white, when it should be black. (00:10:36)
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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