The purpose of the flight was for the pilots to calibrate a newly installed avionic equipment in the airplane. The owner of the airplane was seated in the airplane’s right seat, while the other pilot, who was acting as pilot-in-command for the flight was seated in the left seat. After takeoff, the pilot handed off controls to the owner and requested that the owner perform two 360° turns while he calibrated the equipment. After the two turns, the owner let go of the flight controls and the pilot manipulated the controls to demonstrate the functioning of the g-meter. Both the pilot and the owner believed the other was flying the airplane after this demonstration. After deciding that they would return to the departure airport, the airplane was flying low and almost impacted the ground twice. On both occasions, the pilot pulled up, then once again let go of the controls believing that the owner was flying the airplane. Both expressed discomfort with how the other was flying the airplane, but neither communicated their concerns to the other in a way that was understood, nor did either confirm who was flying the airplane. The third time the airplane neared terrain, the owner called for the pilot to pull up just as the pilot was about to take control of the airplane. The airplane then impacted a field, flipped over, and came to rest inverted. The fuselage, wings, and empennage of the airplane sustained substantial damage. Both the pilot and owner stated that there were no preimpact malfunctions or failures of the airplane that would have precluded normal operation.