Funny but I have that beat.
My buddies ex neighbor comes over and asks to borrow a chain saw he was cutting down a tree. My buddy lends him the chain saw. Few hours later the guy drops the tree, right down through the roof of his barn killing his horse. Same guy next summer ask if my buddy has a sander he needs one cause he is painting his plane to save a few thousand bucks, my buddy lends him an orbital sander. The guy sands all of the rivets off of the plane. Costs him thousands to have the plane re-riveted and painted.
