It's all a rather sad tale actually. He was out caching, and climbed a tree to find a (shall we say) challenging hide when he fell. He didn't fall from a great height, so didn't break any bones but caught his head on the way down and was concussed. Now the poor chap can't remember what he was doing the day before the accident (when he hid the cache).
He doesn't appear to have saved a waypoint in his GPSr, so you'd have thought he would have at least written the coordinates down, but all he had in his pockets was a list of other caches:
It's got to be a clue, but I can't see anything in them. Can you?