The pilot reported that while rolling out about 30 to 40 mph in the tailwheel equipped airplane for the full stop landing, the airplane made a sudden stop and nosed over. The airplane sustained substantial damage to the aft fuselage and tail section during the landing sequence. The passenger reported in a written statement that he accidentally applied the brakes during the landing roll.

The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.