Continuity mistake: Wolverine first enters the sewers by ripping away a fence in the subway. When Jubilee and Gambit follow him, the fence is still intact. When they get closer it is torn again. Odd, really, because on the whole this show has few continuity errors, like self-mending clothes in other cartoons.
The Dark Phoenix (2): The Inner Circle - S3-E12
Continuity mistake: Rogue rips off Donald Pierce's cybernetic left arm, but when he is first shown running away, his right arm is the one that is missing. When he catches up with Sebastian Shaw in the secret passageway, his left arm is back to being the one missing. (00:18:30)
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 flying toward Adler's lab, you can see the building is several stories off the ground. When she flies in through the hole in the roof, the interior of the lab is on the top-level, whereas the previous episode showed that the lab was on the ground level. (00:12:55)
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 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: Bella Donna's engagement/wedding ring from Gambit doesn't appear on her finger until she mentions that she still wears it. (00:10:55)
Secrets, Not Long Buried - S4-E15
Continuity mistake: During the battle at the end, Cyclops uses the crystal statue he brought with him in the fight by throwing it into the air and uses it to refocus his optic blasts on a crowd of attackers. After the battle is over he gives the statue to Dr. Prescott without ever having retrieved it. (00:18:55 - 00:20:20)
The Dark Phoenix (2): The Inner Circle - S3-E12
Continuity mistake: When Cyclops blasts a hole in the floor beneath Sebastian Shaw and causes him to fall through it, Shaw lands on a catering table. Later when Beast jumps down the hole to attack Shaw, Shaw is emerging from underneath heavy rubble rather than a catering table, and he is inexplicably shirtless. The rubble also changes from being brown just before Beast jumps down the hole, and is then white after he lands. Additionally, the floor goes from being black-and-white checkered to a solid brown color. (00:15:55 - 00:17:05)
Continuity mistake: When Pierre is waiting for Gambit in his boat, there is another boat next to his. When he and Gambit take off, the second boat has disappeared. (00:07:55)
'Til Death Do Us Part: Part 1 - S2-E1
Continuity mistake: Beast disarms a member of the Friends of Humanity whilst perched on a street lamp. When the angle changes to a wide shot, Beast is much higher on the lamp post and would have been too far out of reach to disarm the man in the first place. (00:11:45)
Continuity mistake: The exploding playing card that Gambit uses to destroy a few Sentinels and draw the rest above ground is cleverly shown to be the ace of spades (also known as the death card in some folklore), but the card he is shown charging up before the Sentinels see it is the 2 of diamonds. (00:12:10)
Continuity mistake: When Gyrich is in the car trying to get Trask on the phone, he is shown to be sitting in the backseat on the passenger side (note the windows immediately to his right and behind him). When his driver crashes the car into a tree, Gyrich is shown exiting the car from the front passenger seat. (00:08:00)
Continuity mistake: When Wolverine is searching for Sabretooth and the captive Inuits, his arms suddenly turn yellow. (00:15:50)
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 Gambit is saying "Someone may be tracking us," the snaps on both shoulders of his jacket are colored blue, when they should be the same brown color as the rest of his jacket. (00:11:45)
Continuity mistake: When Archangel is lamenting his actions, the communicator devices from Storm's uniform are missing. (00:20:15)
Continuity mistake: When Gambit first walks into Bobby's cell, Bobby is sitting in a chair up against the back wall. A few shots later, Bobby is sitting in the center of the cell. (00:09:55)
Beyond Good and Evil: Part 4 - S4-E11
Continuity mistake: The end of the episode shows Xavier standing with no assistance. The only time in the series that the use of his legs were restored were a side effect of him losing his powers. He has his powers in this scene, so there's not really any reason for him to suddenly have the use of his legs back. (00:19:15)
Beyond Good and Evil: Part 3 - S4-E10
Continuity mistake: When the Four Horsemen are retreating back into the pyramid, the opening is shown to be illuminated. When they are shown entering the opening, it is in darkness. (00:17:15)
