Revealing mistake: When Grievous falls to the ground as the Gungans throw plasma balls at him, the lance General Tarpals stuck through his torso blatantly clips through the ground. (00:15:03)
Iron Forged in Fire: Part One - S1-E1
Revealing mistake: After Tony almost runs into a car after losing control, he flies back up and the road is still shown under him. That group of cars passes and after a brief moment of open road under him, a clone group of the exact same cars in the same lanes pass under him again before the shot changes. (00:16:45)
The Scorn of the Star Sapphire! - S3-E5
Revealing mistake: While in the fight with Major Disaster, the double yellow lines on the road are wrong. They are too thick and close together. (00:12:30)
Revealing mistake: When Cyclops asks Emma Frost what is happening when Shadow King is transferring his consciousness from Storm's mind into Wolverine's, you can see Cyclops and Emma have white outlines drawn around them, indicating they were drawn separately and composited into the shot. (00:19:06)