On August 26, 1995 at 1203 hours Pacific daylight time, a Short Lancair 320, N3204S, was substantially damaged when the pilot lost control of the aircraft during the landing flare, impacted the runway and ground looped on runway 25 at Rio Vista, California. The amateur built aircraft was owned and operated by the pilot. Visual meteorological conditions prevailed at the time of the accident. The personal 14 CFR Part 91 flight was not operating on a flight plan. The private pilot reported minor injuries and the sole passenger received serious injuries. The flight departed from Delano, California, at 1040. The pilot reported that during flare for landing the right wing dropped and contacted the runway despite his efforts to hold the wing up using full left aileron control. The aircraft bounced, the right wing dropped again, and the aircraft veered off the runway to the left and ground looped. The aircraft came to rest headed east, about 1500 feet beyond the runway threshold and 50 feet left (south) of the runway centerline. After exiting the aircraft, the pilot and his passenger noticed that the left wing flap was fully extended and the right wing flap was fully retracted. There were no impact marks on the right wing flap. Inspection of the aircraft revealed that the right wing flap actuating pushrod had broken. The pushrod had a long, smooth "S" bend over its length. In the threaded end of the rod near the rod-end fitting attachment there was a sharp, 85-degree bend where the rod had broken apart. The designer of the aircraft, who sells the aircraft to builders in kit form, stated that the failed pushrod had been superseded by a stronger rod design 4 years prior to the accident in response to operator reports of bent pushrods. At that time, a bulletin regarding the change was sent to kit owners.