A group of hikers were resting at the top of an overlook when one of them decided to get some video of the group with his drone. He set up the shot and the drone started flying slowly away from them getting a nice view of the group. The hiker set his phone (that controls the drone) down on the rock slope then crossed his ankles to relax. He quickly realized, his phone was sliding down the rocky slope but by the time he jumped up and chased it, but it was too late. He must of have recovered either the drone or phone at some point since we are now enjoying the video.