Days of Future Past: Part 1 - S1-E11
Continuity mistake: When Wolverine is telling Bishop that he's not letting him out of his sight, the tubes on the back of his right hand are missing, and then are there in the next shot. (00:17:20)
Days of Future Past: Part 1 - S1-E11
Continuity mistake: When Jean Grey is inspecting Bishop's gear, she isn't wearing any lipstick. A couple of shots later, she is suddenly wearing lipstick. (00:15:05)
Days of Future Past: Part 1 - S1-E11
Continuity mistake: Bishop's goatee is the same color as his flesh when he is first shown sitting down in the War Room. (00:14:55)
The Unstoppable Juggernaut - S1-E8
Continuity mistake: The windshield from Wolverine's jeep is missing when he pulls up to the bank. (00:08:45)
Continuity mistake: When Gambit and Wolverine are about to fight each other, Wolverine's claws are extended, and Gambit has a kinetically charged playing card raised in his right hand. When Rogue intervenes, Wolverine's claws are suddenly retracted, his hands are incorrectly colored white, and Gambit's right arm is down at his side, not holding any card. A couple of shots later, Wolverine's claws are once again extended. (00:07:15)
Continuity mistake: When Jubilee blasts Sabretooth through walls of the War Room and outside, it is shown to be on the mansion's ground level. Many other episodes however depict the War Room to be in the underground levels of the mansion, specifically in the episode "The Unstoppable Juggernaut" where the War Room is still intact after the mansion is destroyed from the ground up.
The Unstoppable Juggernaut - S1-E8
Continuity mistake: When Storm, Rogue and Jubilee are out driving and looking for Wolverine, Rogue's headband is the same color as her flesh. (00:04:45)
The Unstoppable Juggernaut - S1-E8
Continuity mistake: When the team arrives at the destroyed mansion at the end of the previous episode, Cyclops' seat is blue, Rogue says "It can't be" while raising her right hand up to her mouth in disbelief, and Wolverine is growling and extending his claws. When the team is shown arriving at the destroyed mansion at the beginning of this episode, Cyclops' seat is now light-red, Rogue says "It can't be" while her arms remain at her sides, and a silent Wolverine is casually putting on his mask and walking towards the exit ramp of the Blackbird. (00:02:23)
Slave Island - S1-E7
Continuity mistake: When Cameron Hodge is telling Gyrich and Trask about Cable, the books on the table move closer to Hodge between shots. (00:13:10)
Continuity mistake: When Gambit is avoiding the electrified coils in the Danger Room, his normally black and red eyes are colored like a normal person and his gloves are entirely fingerless whereas they are usually only fingerless for the thumb, index and pinkie fingers. (00:02:15)
Continuity mistake: When Storm is having a flashback to her childhood in a fit of claustrophobia, she is depicted as a Caucasian girl with red hair. (00:03:35)
Continuity mistake: When Sabretooth tells Jubilee that her powers are useless if she can't use her hands, the glove on her left hand turns from yellow to brown multiple times. (00:15:50)
Continuity mistake: When Sabretooth is sitting in the hover chair in the War Room, the chair is shown to be hovering up and down in the wide shot, but when a closeup of Sabretooth is shown, the background behind him remains stationary, indicating the chair is also stationary. (00:04:35)
Continuity mistake: When Wolverine says to Sabretooth "Be careful what you ask for," his arms are yellow. (00:17:05)
Continuity mistake: The stains from the tomatoes that are thrown at Beast disappear from his jumpsuit. (00:10:05 - 00:10:55)
Night of the Sentinels: Part 2 - S1-E2
Continuity mistake: When Rogue goes to touch Wolverine with her bare hand to stop him, she is shown removing the glove from her right hand. After Wolverine collapses, Rogue is now missing the glove from her left hand, and her entire left arm, including the hand, is solid green. (00:11:55)
Night of the Sentinels: Part 2 - S1-E2
Continuity mistake: When Rogue catches the security guard from the collapsing tower, he has black hair. When she is flying through the air with him as well as when she dumps him in the grass, his hair is red-orange. (00:06:50)
Night of the Sentinels: Part 2 - S1-E2
Continuity mistake: When Wolverine is playing pool, he scratches the cue ball and the cue ball is then back on the table without him retrieving it. (00:13:35)
Night of the Sentinels: Part 2 - S1-E2
Continuity mistake: Immediately after Storm, Wolverine, Beast and Morph exit the Mutant Registration Center, Beast and Wolverine are shown to be running alongside Gambit and Cyclops. However, mere moments later, Gambit is shown to be blowing up a security fence so Storm, Wolverine, Beast and Morph can rendezvous with Gambit, Cyclops and Rogue. (00:06:45 - 00:07:20)