According to the owner of the airplane, two certificated flight instructors took the airplane out for the purpose of getting one of the pilots a tail-wheel endorsement. The owner stated that while they were on approach to the private grass strip the engine lost power due to carburetor ice. They applied carburetor heat, but inadvertently stalled the airplane which “mushed” and impacted the ground substantially damaging the airframe, and separating both main landing gear. He stated that neither pilot's were injured. Neither the FAA inspector nor the NTSB Investigator were able to speak with the pilot's directly. However, the FAA Inspector was able to speak to their attorney. According to the inspector neither pilot's would admit who was the pilot in command at the time of the accident.