According to the pilot's written statement, after exiting the runway, he proceeded to taxi the airplane to parking. As he pushed the right rudder to make a right turn, the airplane continued straight ahead up an embankment. The pilot reported that there were no mechanical problems with the flight controls. A Federal Aviation Administration (FAA) airworthiness inspector responded to the site and reported that the airplane had come to rest on a 10-degree slope with damage to the horizontal stabilizer. He also inspected the braking and steering system and found no mechanical anomalies.