The pilot/owner of the newly-acquired tailwheel airplane reported that he hired a flight instructor to help him gain proficiency landing on short, narrow runways. He admitted that he was not proficient in this area, although he was current in tailwheel airplanes. He set up for landing on runway 8 with a left crosswind prevailing. He stated that he “arrived too high for the runway.” He stated that the flight instructor did not want him to go around, so the instructor took the controls to demonstrate a slip to lose altitude. The pilot/owner stated that the flight instructor entered a ground loop to the left after touchdown, damaging the airplane. The flight instructor provided a contrary account of the accident sequence. He reported that the pilot/owner had a bad habit of flying with his feet high on the rudder pedals, and he provided guidance prior to the flight to avoid this. Following airwork and takeoff/landing practice at another airport, the pilot attempted a landing at his home airport, which was 2,250 ft long and 40 ft wide. He reported that the pilot/owner, who was at the controls the entire time, overcontrolled the left rudder at 1 ft above the ground during landing, and this occurred so quickly that he was unable to intervene. The right wing contacted the runway, the right main landing gear separated, and the airplane skidded to a stop. A shutdown and egress were then performed. The pilot/owner reported that there was substantial damage to both wings and the fuselage. He also reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation, and the flight instructor did not report any mechanical anomalies in his written statement. A Federal Aviation Administration inspector reported that the flight instructor had no experience in the aircraft make and model prior to the accident flight.