i guess his aim is not that good anymore and he cant do as confident play's as he did...
Im thinking some players spend too much time on screen and their eyes didnt get enough rest and are not as responsive as it could be.
I think spending too much time on pc is counter intuitive.
Just like working out too much at the gym and not taking off days to get a rest.
Actually had problem with my eyes cause i spent too much time on pc and my eyes got very dry and fatigued. Enough sleep and rest between sessions and its good.