Internal FAA policy prohibits ASI’s from occupying any cabin (flight attendant) “jumpseat”, period! An ASI can only occupy a flight deck jumpseat when conducting a cockpit enroute inspection or a PASSENGER seat if conducting a cabin enroute inspection. This is per internal agency orders. So if there was a fed in the 145 cabin jumpseat, that fed was not following protocol and (if reported) could face disciplinary action by his manager. Beleive me when I tell you that they take this stuff VERY seriously.