On May 3, 2011, 1115 central daylight time, a Robinson Helicopter R22 Beta, N927SH, collided with terrain following low rotor rpm near Yancey, Texas. Substantial damage was sustained to the fuselage and tail boom sections. The commercial pilot and passenger were not injured. The helicopter was registered to Prentice Aviation Inc, Bokchito, Oklahoma, and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as an aerial observation flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight originated from a private area approximately 1045. According to a statement provided by the pilot, he was flying an animal control flight over private property. While searching for feral pigs, the pilot was flying 4 to 5 feet above ground level when his passenger notified the pilot of a pig's location. While maneuvering, the pilot heard the engine noise change and the low rpm warning horn sound as the engine began to shut down. The helicopter settled to the ground and rolled onto its right side. While egressing the helicopter, the pilot noticed fuel leaking from the top of the helicopter's fuel tank. While securing the fuel shutoff valve, the pilot noticed that the valve handle was 3/4 the way towards the closed position. The pilot concluded that either the passenger's clothing or seat belt had inadvertently closed the fuel valve which resulted in the loss of engine power when the passenger had moved near the valve. There were no other reported malfunctions or failures with the helicopter. An examination of the helicopter conducted by a Federal Aviation Administration inspector did not reveal any preimpact anomalies. The helicopter was equipped with an older style fuel shutoff valve that consisted of a handle (part number A670-2). A newer fuel shutoff valve was available to be installed (part number A670-1). The newer fuel shutoff valve was remodeled to be spring-loaded towards the open position to prevent inadvertent valve actuation.