Yes, I have seen players, who's gun direction was changing every moment.
But they are not botters (most of all).
They are botters (90% chance) If:
>> If you are not near them, their gun direction was changing every moments at big angles. But when you are near them, their gun direction fixed on your position (you are moving and gun seeking you) and after 0,5-1,0 seconds they preformed excellent shot.
>> They cant move correctly (as a real player). They cant detect killing places and they touch it very often. Or they cant get on some special places (but players easily do that).