When Principal Peskin's boat is found in the pool at the beginning, the words painted on the sail are nice and neat, no paint splatters at all. But later, when it's revealed who painted the sail, the words are sloppy and there are paint splatters.
Pacey sits in the backseat of Deputy Whitter's patrol car, and he opens the door from the inside. In a real police car, the rear doors do not open from the inside. Also, it is obvious the rear door window is completely down, which also does not occur in a real police car.