Eyewitness - S1-E12
Continuity mistake: When the immortal who's trying to kill Tessa snipes at her in Duncan's car, his shot shatters the passenger-side window. When Duncan tails Tessa and her police escort to the safehouse, the passenger-side window is intact. (00:30:05 - 00:35:50)
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.
Continuity mistake: When Grace is crying over Harvey, she is holding a picture of him with her left hand while stroking the frame with her right hand. When the shot changes, she is suddenly gripping the frame with both hands. (00:06:15)