Continuity mistake: When Bella Donna is being selected as the chosen one for the Guild of Assassins, she is flanked by three of her guild members. When the shot changes, the three guild members have disappeared. (00:06:49)
Continuity mistake: When Wolverine enters the infirmary, Cyclops is resting his right hand on his lower abdomen area with his fingers extended. When the shot changes, his hand is a closed fist and has moved closer to his chest. (00:07:37)
Continuity mistake: When Wolverine runs up to Gambit's mini-jet, he puts a considerable amount of distance between himself and Jean Grey, and nearly makes it all the way to the jet and Rogue before the shot changes. When the shot does change, he is suddenly several feet back from where he just was, and Jean Grey is now right behind him. (00:09:01)
Continuity mistake: When Bobby and Pierre enter the basement of the Thieves Guild's mansion, Bobby is on the left, and Pierre is on the right. When the shot changes, they have swapped places. (00:12:43)
Continuity mistake: When Bella Donna is saying the Assassins are prepared for the tithe, a man with long green hair is behind her on her left. When the shot changes, he appears to be standing between her and Gambit. When the shot changes again and Bella Donna is stroking Gambit's hair, he is nowhere to be seen. (00:14:16)
Continuity mistake: When Pierre is telling the Assassins that they betrayed the Thieves, he raises his left arm and points his finger at them, and then lowers his arm back down. When the shot changes, his left arm is raised again. (00:15:00)
Revealing mistake: When Bella Donna is preparing to shoot a blast of energy at Rogue, her body passes through the left hand of the man on her left that was holding her back. Half of her cloak then disappears as she strides forward. (00:14:42)
Continuity mistake: When the Danger Room doppelganger of Omega Red confronts Cyclops, its left arm is pointed down. When the shot changes, its left hand is raised at almost shoulder level. (00:03:01)
Continuity mistake: When the External selects Bobby to be the chosen one for the Guild of Thieves, she turns his jacket red and his gloves gray and fingerless. When he is shown again a few shots later, his jacket is now green, and his gloves are brown, with only the thumbs being fingerless. (00:06:53)
Continuity mistake: When Gambit is saying "You got me in the guild, Bobby," you can see on the wall across the hall that there is a switch that is the same red color as the wall. A few shots later, the switch is now gray. (00:10:18)
Continuity mistake: When Gambit places Bella Donna's ring on the ground, she is nowhere around it. When the shot changes, the ring is suddenly right next to her. Note: this mistake may only apply to the DVD version of the episode, as the version of the episode on Disney+ does have Bella Donna there when Gambit sets the ring down. (00:18:50)
Continuity mistake: In the first establishing shot of the Assassins Guild's mansion, there is a stairway leading up to the front door. In the establishing shot of the mansion in the scene where Gambit is in Bella Donna's bedroom, the stairway is missing, and consequently the mansion's porch area isn't as high off the ground. (00:09:20 - 00:13:20)
Continuity mistake: Shortly after Wolverine, Rogue and Jean Grey enter the Thieves Guild's mansion, they fall down a trap door. However, the trap door is not there when they first enter the mansion, instead only appearing in the shot where they step on it.
Continuity mistake: The two assassins standing guard outside the Assassins Guild's mansion have swapped sides when they let Gambit in the front door. (00:09:25)
Continuity mistake: During Gambit's flashback, the chosen one for the Assassin's Guild is shown to be placing their tithe box on the stump of a tree roughly halfway between the center ring and the outer edge. When the shot changes, the tithe box has suddenly moved to the center of the stump, and the tithe box itself is suddenly wider and shorter and has rotated 90°. (00:05:00)
Continuity mistake: The amount of damage to Cyclops' uniform decreases. When his Danger Room session is first terminated, his uniform is mostly missing around his shoulders and chest. A few shots later, the aforementioned area of his uniform is not as torn up. (00:04:15 - 00:04:50)
Continuity mistake: Gambit's sleeves turn from black to pink when Bella Donna reveals to him that she double crossed the Thieves Guild. (00:13:25)
