Maybe because like me he had to sign a waiver to agree to take responsibility for the mechanic's fines if they got busted while dyno tuning the bike because of the louder exhaust? Or maybe they see signs posted up about how the cops dislike the loud exhaust and the statute? Washington Co is pretty small and the cops have little better to do so it is something they can ticket you for and all they have to do is see your pipes and look for the OE numbers on it.