I think we had a similar discussion during this year's or last year's NCAA tournament. Screener was completely stationary, gave plenty of time and distance. Screened player had no idea screener was there and a fairly violent collision resulted. Screened player went down in a heap, screener continued on his merry way. There was no whistle on the play.
My opinion on the NCAA play was that there was no foul on the play. I saw the Spreewell play only once and can't really remember it well enough to comment.
I'm sure JR can dredge up the link to that old thread.