On February 17, 1999, at 0900 central standard time, a Robinson R22-B2 helicopter, N971SL, was substantially damaged when it impacted terrain following a loss of control while hovering near Freer, Texas. The non-instrument rated commercial pilot and his passenger were not injured. Visual meteorological conditions prevailed and a flight plan was not filed for the Title 14 CFR Part 91 business flight which originated from a private ranch. The helicopter was owned and operated by Smith Helicopters Inc., of Laredo, Texas. According to the operator of the helicopter, a rancher hired the pilot and a trapper to "net some deer on his ranch for relocation." The trapper used a three foot, 18 pound "net gun" which fires a net on to the animal to trap it so that ground personnel can load the animal into a truck for relocation. The pilot stated that the trapper missed a deer with the net and was reloading the net gun while the pilot hovered 20 feet over the deer. The pilot verified that the trapper was ready and started to descend. As the helicopter was descending the pilot noticed the helicopter started rolling to the left. The pilot looked toward the trapper and noticed that the "gun was hooked on the T-bar which connects the two cyclic controls." Consequently, the cyclic control was forced to the "full left" position. The pilot told the passenger to unhook his gun; however, the helicopter impacted the ground on its left side before the pilot could regain control. An FAA inspector examined the helicopter at the site and stated that the tail rotor drive shaft had separated, the main rotor assembly sustained structural damage and that a skid separated from the helicopter. According to the pilot, he had approximately 3 years experience with this type of operation. The pilot estimated that he had accumulated 2,494 total helicopter flight hours, of which 681 hours were in the same make and model as the accident aircraft. The pilot stated that the gunner had many hours experience in the same operation and the gunner was well briefed on the operations of the helicopter.