The Marowak's ability could have changed for some reason. Scrappy, galvanize, pixilate, aerilate, and refrigerate allow the ability wielder to hit ghost Pokemon with normal attacks. The Dhelmise could have been holding a ring target, which removes the holder's type immunities. The Dhelmise could have had its type changed due to something like soak or reflect type. Facade could have had its type changed by something like galvanize, aerilate, pixilate, refrigerate, ion deluge, or electrify.