The Dark Phoenix (3): The Dark Phoenix - S3-E13
Other mistake: When Professor X says "We must do all we can to defeat the Phoenix within her," there is a black spot that moves vertically across the screen as the camera is panning from Cyclops to Wolverine. It's as if there was a small bug on the lens. (00:11:00)
Other mistake: When Apocalypse is holding Rogue upside-down, her belt remains in place despite the fact that her belt is wider than her waist and abdomen (it is not as wide as her hips which is why it remains in place when she is upright). Her belt should have fallen down to underneath her breasts. (00:11:50)
Dark Phoenix (1): Dazzled - S3-E11
Other mistake: When Rogue is looking down at the Inner Circle from the skylight, a hair appears on the animation cel, in the glare of the glass to the left (viewer's right) of her head. (00:18:14)
Dark Phoenix (1): Dazzled - S3-E11
Other mistake: When Wyngarde is facing the wall after White Queen breaks his mental contact with Jean, he is casting a shadow against the wall. However, as the White Queen approaches him, she has no shadow of her own. (00:15:17)
Dark Phoenix (1): Dazzled - S3-E11
Other mistake: The episode begins with an out-of-place one-second shot of a door opening on a space craft revealing a satellite hovering over Earth before quickly cutting to an establishing shot of Muir Island. Note: this may only apply to the version of the episode that appears on Disney+. (00:01:00)
Savage Land, Strange Heart (2) - S3-E9
Other mistake: When Storm is directing a surge of lightning at the monolith of Garokk after telling Rogue to stay back, the plume of smoke coming from the volcano in the background is completely motionless. (00:16:49)
The Phoenix Saga (4): The Starjammers - S3-E6
Other mistake: When Captain Britain is shown flying by the Elizabeth Tower, the two clocks visible are displaying different times. The clock on the left is showing roughly 12:10, while the clock on the right is showing 12:00. (00:04:50)
Other mistake: When Wolverine is leaving to find Yuriko and Jubilee offers to tag along, the camera is fluttering in and out of focus for a few seconds. (00:07:01)
Other mistake: When Wolverine first enters the subway, there are two tracks, and there is a train moving away from the camera on the track closest to the platform. When Gambit and Jubilee enter the same area moments later, there is now a train on the same set of tracks, but moving towards the camera. (00:07:38 - 00:08:07)
Weapon X, Lies, and Video Tape - S3-E19
Other mistake: The pickup truck Beast is driving appears to be missing its foot brake. (00:18:50)
The Juggernaut Returns - S3-E17
Other mistake: During the "Previously on X-Men..." segment before the show's intro, it shows the Juggernaut landing in the ocean and walking across the ocean floor after Gladiator had hurled him away. However, Juggernaut's fate was never actually shown after Gladiator threw him. He was only seen fading off into the distance. (00:00:50)
Other mistake: When Corsair is running towards the Starjammers and Storm at the top of the Mayan structure, Lilandra can be seen among the group despite the fact that she was not in the episode before or after this moment. This was most likely supposed to instead be Jandra, the Shi'ar child that the Starjammers were trying to protect. (00:18:50)
Other mistake: When Cyclops blasts Iceman with his optic beam, the image of Wolverine encased in ice remains on-screen, when it looks as if the shot was supposed to completely change to Iceman getting knocked back by the blast. (00:05:35)
The Dark Phoenix (2): The Inner Circle - S3-E12
Other mistake: When Wolverine lands on Leland with his claws extended, if you look closely you'll see that Wolverine's left hand ends up in Leland's chest area, yet Leland was not impaled by the claws like he should have been. (00:17:15)
Dark Phoenix (1): Dazzled - S3-E11
Other mistake: When Moira McTaggart asks Jean what happened to her, keep an eye on Banshee. His body slightly stretches horizontally for a split-second. (00:01:15)
The Phoenix Saga (3): Cry of the Banshee - S3-E5
Other mistake: When the text depicting the episode name appears on screen after the opening credits, it says "The Phoenix Saga Part 2, The Cry of the Banshee." It should read "The Phoenix Saga Part 3, The Cry of the Banshee." Note: this mistake may only apply to the DVD version of the episode. The episode that appears on Disney+ correctly depicts it as "Part III." (00:02:20)
The Phoenix Saga (4): The Starjammers - S3-E6
Other mistake: When the X-Men and Corsair encounter D'Ken in the hallway, D'Ken, Gladiator and Lilandra remain in the background while the X-Men and Corsair are wiped from the screen. It's as if this was meant to be a zoom in on D'Ken, Gladiator and Lilandra, but their size relative to the camera remained the same and the X-Men and Corsair are simply removed from view. (00:19:35)
The Phoenix Saga (4): The Starjammers - S3-E6
Other mistake: When Gambit is tossing playing cards in Lilandra's helmet, he is shown tossing four cards. All four cards are the exact same card (the ace of spades). (00:13:30)
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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