One minute Bart is wearing a T-shirt that belonged to the Flanders, the next he is wearing his traditional red one again.
Maude's lipstick disappears and reappears between shots.
When Kearney shows the left-handed pinking shears stolen from the left handed emporium, the blades aren't reversed as they should be from right handed pinking shears.
Bart's T-shirt should say "MAUDE LOVES NED" but actually says "MAUDE LOVES NEL"
At the end, Homer toasts Ned as "the richest left-handed man in town", even though Mr. Burns is standing right there.