Revealing mistake: When the episode ends and the cop's car arrives, check a leaf on the floor that serves as a T‑mark. When the car stops, Sally walks right to that spot.
Suggested correction: If it was tape or some other marking that would not logically be there, it would be a mistake. A single leaf, which she happens to walk up to, is not. Even if the leaf was being used as a T-mark, it isn't a mistake. The reason the filmmakers do something is only irrelevant unless it breaks the reality of the scene.