It wasn't luck, it was stupidity on Faber's part. Faber threw a wild elbow that only a moron would ever throw. That is something like I would expect from Charlie Zellenoff, when he said he was going to MMA.
Mike Brown is a very very good fighter guys, hes at least a top 5 guy, the only thing keeping him from being the undisputed #2 before the fight was Imanari leglocking him a while ago (no shame in that) This wasn't GSP - Serra, it was a legit top 5 guy beating the #1 guy.