Just wandered onto this thread, and I know it happened, to a member of my flight school training class. It was on a pinacle at Ft. Wolters, Texas, in 1968, and the student set down to take a P. We were trained to friction the controls and get out to do an LZ recon back then, quite normal. The aircraft was an OH-23. While the student was downslope a bit doing his business, the helo became just airborne enough to slither down the hill and beat itself to a pulp. The pilot (whose name shall not be devulged here!) stood on the top of the hill and waved for a long time before anyone saw him.