There is a simple explanation. Sometime when you hurt something it "effects the brakes more than the gas". Chris Wells even said this after he hurt his ankle the first time.
I have had an injury close to this. I could run and do just about anything, but when I went to slow down the thing hurt bad. When I walked it hurt as well, because the act of walking compared to running has a little more of a plant which is what sets it off.
So, I would imagine Wells can sprint, is ok cutting, and it still is a pain to stop or walk.