The student pilot had recently purchased the airplane and requested the airline transport pilot (ATP) assist him flying it back to his home airport. During an enroute stop, the ATP pilot reported that during the landing roll, the airplane became uncontrollable and veered off the left side of the runway, striking a runway sign, which resulted in substantial damage to the right horizontal stabilizer and elevator. The pilot reported that he believed there might have been rigging or tailwheel mechanical issues with the airplane. A visual examination of the brake system performed by a Federal Aviation Administration (FAA) inspector did not reveal any damage, however, the brakes were not tested. The NTSB was not notified of the accident until five months after the occurrence which precluded further examination of the brake and tailwheel system. According to an FAA inspector who reviewed the maintenance records and interviewed people familiar with the airplane’s history, the airplane had been flown about 10 hours in the previous 10 years. The condition inspection, accomplished about 2 months before the accident by a mechanic, revealed the airplane was “squirrely and sensitive” on the controls, but he considered the airplane airworthy. About a month before the accident, the brakes had been rebuilt, and the airplane was returned to service. The ATP pilot, who had never flown this make and model before, reported that he confirmed the airworthiness of the airplane prior to departure, however, he also reported to the FAA inspector that the airplane was not acting right during two takeoff attempts, before the third successful takeoff attempt that initiated the accident sequence. The accident likely could have been prevented if the pilot chose to further investigate the anomaly he experienced on the ground, rather than continuing the flight.