Continuity mistake: When Cable has broken into Warren's lab from the balcony, the doorknobs on the double-door are intact. As the scene progresses, one or both doorknobs will disappear and reappear, and the broken glass on the one door will be intact. Additionally, when the opened door is first shown, there are a couple of broken pieces of glass on the floor next to it. When the shot changes, the pieces of glass are gone. (00:02:35 - 00:04:30)
Continuity mistake: When Cable blasts Warren off the balcony, Warren falls and drifts into the snow a couple feet, leaving an impression of his shape in the process. When he recovers, he emerges from completely under the snow as if he were buried, but the impression is still there in the snow moments later when he retreats, so it could not have refilled itself with fresh powder and buried him. (00:03:10 - 00:04:30)
Continuity mistake: When Cable grabs Warren through a shelf on his bookcase, he knocks several books onto the floor. When Warren pushes the bookcase over, there is an overhead shot of the floor surrounding the bookcase for several feet in each direction and there are no books visible on the floor. (00:02:50)
Continuity mistake: When Warren shoots his blaster through the bookcase, the blast goes through some books/file folders that say "DNA Test 6" and "DNA Test 7" while "DNA Test 4" and "DNA Test 5" are warped out of shape. When he pushes the bookcase over, the two warped books/file folders are back to normal. (00:02:50)
Continuity mistake: When Warren's girlfriend is saying "They say you keep a mad scientist up here," the earring on her left ear goes from being comprised of five gray circles, to four, and then back to five in the same shot. Both of her earrings are then comprised of four circles for the remainder of the scene. (00:02:10)
Slave Island - S1-E7
Continuity mistake: After Gambit jumps out of the moving hovercar, it comes to a stop in the middle of the road. When the shot changes, the hovercar is suddenly on the left side of the road (note the yellow lane dividers), and is no longer casting a shadow. (00:12:00)
Slave Island - S1-E7
Continuity mistake: When Gambit tries to grab the gun, Cable stops him by placing his left foot on top of it. When the shot changes, it is now Cable's right foot that is on the gun. Additionally, yellow lane dividers in the middle of the road disappear when Gambit first reaches for the gun, and then reappear a couple of shots later. (00:12:15)
Slave Island - S1-E7
Continuity mistake: When Storm is asleep, her lightning bolt earrings appear to be connected through the back of her earlobes. When she wakes up, the earrings are now on the front of her earlobes. (00:20:15)
Slave Island - S1-E7
Continuity mistake: When Cyclops is trying to radio Professor X from the Blackbird, there is a window immediately to Cyclops' right. When the shot changes, Jean Grey is suddenly seated on Cyclops' right. (00:20:00)
Slave Island - S1-E7
Continuity mistake: When the Genosha guard tries pulling a gun on Cable, you can see his headgear only extends down to his jawline and chin. When Cable picks him up and throws him, his headgear is now also covering his entire neck. (00:19:00)
Slave Island - S1-E7
Continuity mistake: When Cable shoots his exploding plasma blast at the conference table, the blast is shown coming through the window from a downward angle. However, the tree branch that Cable is subsequently shown to be using as his vantage point is lower than the window, so the blast could not have come at a downward angle. (00:14:45)
Slave Island - S1-E7
Continuity mistake: When Gambit is carrying Jubilee over his shoulder, the placement of his hand alternates between being on the small of her back, the back of her thighs, or her butt depending on the shot. (00:13:55)
Slave Island - S1-E7
Continuity mistake: After Gambit unlocks his collar, he lets the collar fall to the ground. In the next shot, the collar is visible on the ground a couple feet in front of him. In the shot after that when he retrieves the gun, the collar is no longer visible on the ground. (00:12:50)
Slave Island - S1-E7
Continuity mistake: The keyhole on Gambit's inhibitor collar alternates between being mostly the same yellow color as the rest of the collar, and being gray such as when he unlocks it.
Slave Island - S1-E7
Continuity mistake: When Gambit is being escorted into the Sentinel factory, he has two guards behind him on his right and left. When the shot changes, the guards have disappeared. (00:11:00)
Slave Island - S1-E7
Continuity mistake: Throughout the episode, the inhibitor collars worn by the captured mutants alternate between having a leveled edge like a hardware nut, to having a rounded edge like a finger ring.
Slave Island - S1-E7
Continuity mistake: When the Sentinel puts Jubilee in the detention box, it is still dark outside. A couple of shots later and there is a considerable amount of daylight in the sky. (00:09:30)
Slave Island - S1-E7
Continuity mistake: Before the mutants ambush the guards, they are walking in a single-file line, with Sunfire in front, followed by Jubilee, Mystique, Caliban, an unnamed female mutant, and Aurora. A couple of shots later, either Aurora or her similarly-dressed twin brother Northstar is suddenly at the front of the line. (00:08:55)
Slave Island - S1-E7
Continuity mistake: When Cyclops hangs up the phone, he is standing next to a table on which the phone is located. When the shot changes, either the table has disappeared altogether or Cyclops has suddenly moved several feet away from it. (00:06:10)
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