While that sucks it's understandable. One, he exaggerated the knee with a wind up so that it attracted so much attention the down fighter saw it coming and the ref couldn't miss it. The fighter in dodging it made it impossible to know in real time if his head kicked back to avoid or because it took a shot.
Lesson: Don't throw knee bombs at a guy that is obviously in a position making them illegal.
Aldo is one of the fastest strikers I've ever seen in MMA. The guy is fast enough to use leg kicks as counters to both punches and kicks, landing them before the strike he is countering reaches him and often knocking his opponent off their feet. That's is crazy quickness when you can react to an attack and land yours first.
Having said that Faber is the perfect foil... he's a power fighter that can take you to the ground and pound you out. He's not some bum that will simply attempt a take down either, he's damn good and stronger than his size would suggest.
It will be interesting... I'm going with Aldo on this one. The guy is the latest crazied brazilian hell bent on kicking the worlds ass one victim at a time. There must be something in the water over there.