On June 29, 1995, at 1100 central daylight time, a Piper PA-28R-200, N1394T, was substantially damaged during landing near Denton, Texas. The certificated flight instructor and his 3 passenger were not injured. The flight originated at Fort Worth, Texas, at 1030, as a student orientation flight. The aircraft was being operated under Title 14 Part 91. Visual meteorological conditions prevailed at the time of the accident. In an interview conducted by a Federal Aviation Administration inspector and in a written report, the pilot reported that during the landing roll, the passenger, seated in the left seat, "applied strong uneven constant pressure" on the left toe brake. He further stated that he could not counteract the braking because the airplane was not equipped with toe brakes for the right seat; however, he did attempt to apply rudder control. Subsequently, the aircraft "skidded" off of the left side of the runway and the right main landing gear collapsed, resulting in structural damage to the right wing spar and fuselage.