The purpose of the flight was for the pilot under check to obtain a tailwheel undercarriage endorsement. Prior to take-off, the pilot under check was briefed that due to the instructor's seating position, he was unable to apply full rudder pedal travel. Therefore, rudder control would have to be exercised by the pilot under check. During a demonstrated short field landing by the instructor, the pilot under check did not take control of the rudder on the ground as briefed. Directional control of the aircraft was lost despite calls by the instructor for the pilot to check the swing and use brake. The aircraft left the strip and was substantially damaged. The reason why the pilot under check did not take control of the rudder pedals during the landing was not determined, as he refused to co-operate with the investigation.