The pilot in command, who was also the owner of the aircraft, was acting as the safety pilot for the other pilot, who had only recently received training on the aircraft. This was the first occasion on which the co-pilot had flown the aircraft from the right hand seat. He flared the aircraft too high on the first circuit and was advised by the pilot in command that the flare had been commenced too early. As he attempted to reposition the aircraft closer to the runway it struck the runway heavily and bounced. The co-pilot inadvertently closed the throttle and the aircraft struck the runway in a nose down attitude. Damage was caused to the propeller, engine firewall and the landing gear.