I think there is a little bit of a difference between being pulled over during a traffic stop (that gets discussed more than just about anything on DC as far as police contact goes) and flagging an officer down over a parking problem. Traffic stops are amongst the most dangerous things police officers do, parking problems? not so much. If your state laws dont require you to inform, then good to go - sounds like a pretty typical encounter. If your state laws to require you to inform (they do here) then make sure that you do.