Sequence of Events
During a multi-engine instructional flight, the pilot-under-instruction (PUI) occupied the left seat and the flight instructor occupied the right seat. The PUI was performing a simulated engine-out approach, with the right engine set to zero thrust. On short final, the airplane's airspeed began to decrease. The instructor instructed the PUI to add power, which he did; however, the airplane drifted to the right due to insufficient rudder input. The instructor announced that he was taking control of the airplane, took control, and the PUI relinquished control.
Because of the low altitude and with the airplane stabilized, the instructor decided to land the airplane in the grass next to the runway. However, the PUI grabbed the yoke, pulled back on it, and started screaming. Both pilots struggled for control as the airplane went below minimum control airspeed. The airplane then struck the ground in a high right-angle of bank.
Background
Prior to the accident flight, the instructor had called an examiner to cancel the PUI's upcoming check ride. During that conversation, the instructor characterized the PUI, when flying, as unpredictable and someone who would "do unusual things on his own."