@Tai Chi,
Remember this photo?
If you were going up on a roof of this height, what's the first thing you'd do?
If you answered, "Tell someone I'm going up on the roof," congratulations -- you're smarter than Mr. Fix-it.
There's me, relaxing near the end of a busy day, when I hear all this banging and clattering and I figure he's dislodged a stack of lumber in the lean-to and I'd better go see how deep he's buried. Turns out the upper ladder slipped while he was tying off, leaving him hanging from the roof peak over the lean-to (you can see the scrape marks where the ladder slipped down the wall). Since he wasn't tied off yet he eventually had to let go. Didn't break anything. Didn't learn to fly either. Scraped up one hand pretty badly on the edge of the metal roof.
The great thing about obsessive personalities is they accomplish a lot. Sometimes they need to be reminded they're mortal!