It looks like this is either the homeowner, or other flavor of non-professional, wearing shorts, but no shirt/climbing harness/flip-line/spurs, or helmet. There's a WHOLE LOT of physics intelligence/experience needed to survive as a tree trimmer. In my early 20's I invested in the gear with the aim of following that line of work... after doing a few jobs, I determined that having a rapidly moving saw chain at neck/head level while topping trees was NOT my cup of tea. I really hope this fellow comes out alright, but his head dropped at least 20' to 24', and to land on your back on a downed log, it would be a miracle if he survived without major injuries, and that's not even considering the head injuries from the initial head-smack of the falling trunk. Don't try to save a few bucks doing your own tree work if you don't know what you're doing.