First off, no one is 100% going into a fight. Sparring, mat work, lifting, conditioning, everything takes a toll. Lots of guys win fights nicked up and dinged. They only talk about the injuries when they lose.
Silva has most definitely been exposed. All it takes is one guy. To get dominated the way he did is a real eye opener.
As far as him catching Sonnen, that was more Sonnen's fault than some "slick" BJJ by Silva. Sonnen postured up and left his hands in a lazy position. This is shit you learn in the first week of ground fighting. Truth is all Sonnon had to do was lay on Silva for the 5th round and he's the champ but he chose to fight and I respect that. Silva's reign as champ will be coming to an end soon.