[Adam]

Even a screener has the same rights to a spot on the floor. Any player getting in the path of an opponent is either a screener or a guard. If his team has the ball, he can't be a guard.
So, after the initial screen, when the screener cuts to the basket, he may become a screener again if his movement places him in the path of a defender.
I'm not there to judge poor defense or poor offense, so even if the defender is a bit slow, it doesn't matter.

The problem is, the pick and roll is often taught as a seal off type move, where the screen rolls in such a way as to seal off the defender by moving into and obstructing his path. That's typically a foul, and just because the screener has his hands up looking for a pass doesn't mean he isn't guilty of an illegal screen.