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 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)
Other mistake: When the Lady Gardener touches the flower on her table, it instantly dies, which elicits a shocked reaction from her. This show establishes that mutant powers begin to manifest during puberty, and this character is middle-aged. A character that has been living with their powers for that long shouldn't be shocked at what her powers do. (00:03:56)
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 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 Cyclops forces his way to the front of the crowd to confront Warren Worthington (Mystique in disguise), the Lady Gardener is standing just behind the mutant with the bowl-cut hairdo. When the shot changes, the two are suddenly standing next to each other. (00:04:30)
Continuity mistake: When the three horsemen are climbing onto their mechanical horses, Famine's horse is in the middle, and Pestilence's horse is on the right. Once all three have all been individually shown to be mounting their horses, Famine and Pestilence have swapped places. (00:06:08)
Continuity mistake: When Apocalypse is saying "Go forth my horsemen," his right arm is raised up. When the shot changes, his right arm is immediately at his side. (00:06:30)
Continuity mistake: When Rogue and Gambit are playing pool and Rogue is getting ready to try and sink the 8-ball, the cue ball is shown to be close to the corner pocket and its rail. When the shot changes, both balls are suddenly further away from the pocket and the rail. It's an instantaneous change, so it can't be a matter of the cue ball rolling. (00:06:45)
Continuity mistake: When Rogue tries to sink the 8-ball, the ball comes to a dead stop just in front of the side pocket. When Gambit goes to take his turn, the 8-ball is suddenly near the center of the table. (00:07:00)
Continuity mistake: When Rogue turns her head to face Jean Grey, some of her brown locks of hair turn white. When she turns back to face Gambit, the white locks become brown again. (00:07:20)
Continuity mistake: When Storm is teasing Gambit for damaging the pool table, she is holding a television remote in her left hand, which is yellow (Storm doesn't wear gloves). A couple of shots later, she is holding the remote in her right hand (she had time to transfer the remote to her other hand, so no mistake there), which is colored correctly. (00:07:35)
Continuity mistake: When the news reporter is first shown talking about the World Peace Conference, he has one blue eye and one brown eye. For all remaining shots he is in, both of his eyes are blue. (00:07:40 - 00:08:35)
Continuity mistake: When Storm is first watching the World Peace Conference on TV, she is sitting on a couch in a rec room. Moments later, she is watching in a hallway while standing. (00:07:45 - 00:09:00)
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 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 the conference chairman is first shown at the podium, there are five microphones attached to it. A few shots later, there are only four. (00:07:55)
Continuity mistake: When Storm is watching TV with her arms folded, her left hand shows her index and middle fingers touching. When the shot changes, it is her middle and ring fingers that are touching. (00:08:40)
Continuity mistake: When Apocalypse is ordering War and Archangel to attack the tanks, Archangel's decollete is the same light blue color as his skin, when it should be the darker shade of blue that his outfit his, since his outfit leaves his face and hands exposed. The photograph Xavier shows Rogue of Archangel later in the episode also depicts the same error. (00:09:30 - 00:11:12)
Continuity mistake: When the tank is falling through the hole in the bridge, the tank's gun barrels are pointed towards the water. When the shot changes to the tank landing in the water, the gun barrels are pointed towards the sky. (00:09:40)
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.
BaconIsMyBFF