The pilot was receiving instruction for his tailwheel endorsement. While the flight instructor and pilot were landing the tandem-seat, tailwheel-equipped airplane, the airplane bounced. The flight instructor communicated to the pilot “my controls” and blocked him (using the rear seat control stick) from pushing the front seat control stick forward, so that the flight instructor could transition from a bounced wheel landing into a three-point landing. The flight instructor stated, the pilot did transfer control to the flight instructor but didn’t take his feet off the brakes. The pilot stated he was unfamiliar with using heel brakes and applied to much pressure to the brakes, “upon touch down after the bounce we nosed forward and flipped onto our back,” resulting in substantial damage to the rudder. The pilot reported that the airplane had no preimpact mechanical malfunctions or failures that would have precluded normal operation.