Cutting down trees is nearly a science--do X to a tree so it'll fall in Y direction. But for everyone who's ever put an axe or chainsaw to a tree, the second worst moment in the world is the one when you realise you SCREWED UP.
This first poor guy almost sacrificed his roof with his careless mistake. But the worst feeling comes when the tree suddenly decides it's coming down NOW. Pro lumberjacks call it the "Crazy Barber Chair," but it'll snip off more than just your hair!