Factual error: After Wolverine falls into the ocean, he surfaces and grabs onto a platform of ice just after Sabretooth gloats about defeating him. Since Wolverine's skeleton is coated with a heavy metal, he wouldn't be able to surface. He would sink to the bottom and at the least have to resort walking to the nearby cliff wall and using his claws to scale it until he is back on the ground. (00:03:48 - 00:04:24)
Continuity mistake: When Archangel is lamenting his actions, the communicator devices from Storm's uniform are missing. (00:20:15)
Other mistake: Rogue's CGI model in the outro is missing the white streak in her hair.
Continuity mistake: When Trask turns the laser onto the propane gas tank, it is on Master Mold's left. When Master Mold reaches down to try and stop the laser before it causes the tank to explode, it is now on his right. (00:16:04)
Continuity mistake: When Rogue is calling out to Gambit just before Jean and Senator Kelly exit the mine shaft, the X logo on her chest is a yellow X on a red background, when it should be a black X on a red background. (00:17:57)
Days of Future Past: Part 2 - S1-E12
Continuity mistake: When Mystique starts walking away from Rogue, her footsteps are audible, and she takes about four steps. When the shot changes to a closeup of Rogue asking why Mystique tried to turn her into one of Apocalypse's slaves, if you listen carefully, you can hear Mystique take about ten more steps. When the shot changes again, Mystique is suddenly only a couple steps away from Rogue. (00:18:58)
Continuity mistake: When Jean is using her telekinetic powers to rescue Senator Kelly from Master Mold's lab, she drops him on the floor in the middle of the lab. When Cyclops gets blasted by Master Mold after he and Jean run to grab Kelly, Jean and Kelly are suddenly inside the mine shaft. A couple of shots later, Jean and Kelly are now standing at Master Mold's feet. (00:15:42)
Continuity mistake: When Gambit is asking Xavier why the X-Men must all die to save Senator Kelly, the top of Wolverine's mask is incorrectly colored blue. A few shots later, this portion of the mask is correctly colored yellow, but then the portion of his mask by his right cheek is also yellow, when it should be black. (00:09:48)
Days of Future Past: Part 2 - S1-E12
Continuity mistake: After Blob knocks Cyclops to the ground, Jean helps him up, and the two of them are standing a step away from Blob. The shot changes to Blob pointing and laughing for roughly a second, and when the shot changes again, Cyclops and Jean have disappeared, with not enough time to have moved offscreen. (00:12:20)
Continuity mistake: When Master Mold is telling Trask that mutants are humans, Trask's right hand is raised near his face. When the shot changes, his hand is suddenly lowered at about waist-level. (00:15:11)
Revealing mistake: When Jubilee is saying "What's anybody waiting for," her arm passes through Wolverine's body. (00:10:40)
Continuity mistake: When Trask's voice is first heard coming from Gyrich's cell phone, the phone is in the top left corner of the floor tile. When the shot changes, the phone is now in the center of four smaller tiles. (00:09:12)
Continuity mistake: When Gyrich's gun slides over next to Cyclops' feet after Wolverine tackles him, you can see Cyclops, Rogue, and Storm are standing at the entrance of the Lincoln Memorial. When the shot changes, the three are no longer near the entrance. (00:09:07)
Days of Future Past: Part 2 - S1-E12
Continuity mistake: When Xavier's watch magnetically clings to his hoverchair, the body of the watch is pointing at 1 o'clock. In the next shot, it is pointing at 12 o'clock, the minute hand has advanced roughly 4 minutes, and the watch has also moved down the chair and to the right a few inches (note the contour lines on the chair as the visual cue). (00:20:39)
Days of Future Past: Part 2 - S1-E12
Continuity mistake: When Storm is saying "It is the only way to be certain," the pointed end of her right earing is briefly square-shaped. (00:07:53)
Days of Future Past: Part 2 - S1-E12
Character mistake: After Gambit escapes from Wolverine and Bishop, Bishop says to Wolverine "No wonder you sent me back to change the future, because everything that happens is your fault." Wolverine didn't send Bishop back to change the future. He insisted on going back himself, but Bishop forced Wolverine out of the mission and inserted himself into the role because he felt Wolverine was too old to succeed. (00:10:03)
Days of Future Past: Part 2 - S1-E12
Factual error: The U.S. flag has 13 stripes. When Bishop is telling the X-Men how Gambit's betrayal will affect the future, the flag shown flying outside the Capitol building is missing two stripes. In the next shot showing the flag draped over the coffin, it has at least 17 stripes. (00:04:25)
Continuity mistake: When Beast is first shown in his prison cell, the X logo on his waistband is black with a red background. When Jubilee hugs him, it is now a red x on a yellow background. (00:19:51)
Factual error: When Senator Kelly is giving his campaign speech, the U.S. flag behind him is missing one stripe and has at least two too many stars. (00:19:30)
Continuity mistake: At the beginning of Senator Kelly's campaign speech, his campaign button is predominantly white with some blue at the top and bottom. When the shot changes, the majority of the button is now blue, with only a small portion in the center being white. (00:19:20)
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