The rated pilot and flight instructor were practicing off airport landings in unimproved areas in the tailwheel equipped airplane. After two evaluation passes, the pilot landed. The pilot reported that during the rollout the airplane had oscillations around the lateral axis and the pilot applied the brakes. The flight instructor also applied brake pressure during the landing roll. The airplane nosed over and came to rest inverted. The airplane sustained substantial damage to right wing strut, vertical stabilizer, and rudder. The pilot reported no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.
The pilot reported the accident may have been avoidable with better communication and transfer of controls with the flight instructor.