Poor guy, very sad that it takes a fatality to remind us all of the dangers of operating on steep ground ........you can never be too careful when operating equipment, all it takes is 1 small oversight or equipment failure ......
A similar tragedy happened locally here a few years ago, a guy mowing across the slope around his small pond (something he'd probably done for many seasons before) on a 15hp ride on which slippped sideways & rolled into the pond, trapping him by the leg & was found by his family a 1/2 hour or so later drowned.... the inquest found the mower hydro transmission was in poor conditon & failed at a critical moment allowing the unit to basically "slide" & roll into the pond.