Born Again Krabs (aka A Penny Saved) / Safety Freak (aka I Had An Accident) - S3-E17
Revealing mistake: I Had An Accident: When the gorilla is beating up Patrick and Sandy in the bag, in some shots, there are faint lines on the screen due to the green screen being cropped incorrectly. In addition, when the gorilla smashes the chair onto the bag, some pieces of the chair cross one of the lines and disappear. (00:21:02)