Continuity mistake: In "The Graveyard shift", Squidward begins to count the signals that means the ghost will appear. "First the lights, then the phone.", and a green slime appears in the wall. Squidward says "Oh, wait, they always do that, but what was the third thing?", and the bus appears at the front of the Krusty Krab. SpongeBob says, "I didn't know the bus comes here at this hour", and look at the wall: the green slime has disappeared.