One of Stan's greatest strengths, literally, are his freakishly strong legs. I doubt there are many 197 pounders with legs stronger than his - and this is from weight room inside info. And if that is one of his major strengths, I'm sure he has become accustomed to pushing through certain moves mostly with lower body strength. Then when he suddenly can't utilize that superior leg strength the way he's used to, that changes the way he has to wrestle. He may have hesitated pushing through a move because he could feel that the knee wasn't going to support it.