Neither do I. How could the meteorite hit his and only leave a scar, but have enough force to not only knock him over but leave a crater in the ground? Doesn't make much sense to me. He's probably misremembering. Seems more likely that the meteorite first hit the ground, the impact of which knocked him to the ground, during or after which either the meteorite ricocheted into or a piece of debris hit his hand.
A rather lazy piece, in my opinion. It doesn't deliver any new or critical analysis of Facebook or anything to do with it. Rather, it simply compiles previous articles written about the social network into a single, pessimistic piece. It's a lame literature review.
edit:typo
