Continuity mistake: When Wolverine is telling Morph that Scott and Jean will be leaving the team after their baby is born, the toothpick in his mouth swaps sides.
Continuity mistake: When Carl Denti grabs Roberto's face, his thumb is near the corner of Roberto's lips. When the shot changes, his thumb is now on Roberto's cheek.
Deliberate mistake: When the news program is discussing Gyrich's assassination attempt on Xavier from the series finale of the original animated series, he's shown to have his classic look of auburn hair and sunglasses. However, when this scene occurred, Gyrich had black hair and was not wearing sunglasses. This was done deliberately to match the character design of the original series prior to the final 6 episodes, when Saban took over and redesigned much of the show's look.
Mutant Liberation Begins - S1-E2
Audio problem: When Magneto is saying, "For an old friend has challenged me to remember this view of Earth," his mouth is closed for the last two words.
Mutant Liberation Begins - S1-E2
Audio problem: When Magneto is saying, "Should I successfully vindicate myself in what I will generously assume is a fair trial," his mouth movement is out of sync with some of the dialogue.
Bright Eyes - S1-E7
Other mistake: SPOILER: Gambit's funeral is taking place in his hometown of New Orleans, as evidenced by the coffins being above ground (because New Orleans is at or below sea level). However, Gambit's coffin is oddly lowered into the ground.
