In all aeroplanes which are equipped with a flight crew compartment door in accordance with 13.2.2:
b) means shall be provided for monitoring from either pilot's station the entire door area outside the flight crew compartment to identify persons requesting entry and to detect suspicious behaviour or potential threat.
What is the definition of a pilot's station, cockpit or flight deck are clear definitions. Clearly, though not convieniant one member of the flight crew can get up and look through a peep hole. Granted the "either pilots station" part is what you are cherry picking and arguable but arguably one can get up and look based on intnl standards.