I love it when rich people mess stuff up and can simply say, "Well, at least that was my fault." Such was the scene when Las Vegas casino-magnate Steve Wynn accidentally punched a hole into a $139-million Picasso painting that he had just sold to a collector. Wynn's got some kind of degenerative visual disease that messes with his peripheral vision, and apparently, while standing next to the painting and gesturing at something else, he inadvertently brought down his elbow on to the canvas, puncturing it with a hole about the size of a quarter (according to witnesses).
Brian's question is a good one: does that make the painting more valuable, or less so? It is still a Picasso, and now it's a Picasso with more history. Conversely, now it is a ruined canvas. Art people of the world, educate me. I would say that, obviously, the sale was voided, and now Wynn is still the proud owner of one of the art world's biggest oopses, but I can be argued away from that stance.