The Great Bank Robbery - S4-E6
Revealing mistake: The bandits lock Bo and Luke inside closed coffins and then leave. Bo and Luke begin "rocking" the coffins back and forth to tip them over so they can escape. However in the following shots, as Luke is rocking inside his closed coffin, the camera slips or shifts too much, and you can see the barns' interior at the sides of the screen, alongside some equipment.
Revealing mistake: In the closeup of Twiki, you can see Felix Silva's mouth in the mouth grille.
Winds of War - S1-E8
Revealing mistake: When the widow is bandaging the fighter pilot, the part of bandage she is wrapping appears and disappears during the animation - when her hand movies, instead of adding new layers of bandage, the army causes the green sleeve of the space suit to flash back in view. (00:20:10)