Defender setting a moving screen...

[w_sohl]

This has happened to me twice and both time coaches complained. The defender noticing that an offensive player is coming backdoor steps into the path of the player to set, what I would consider a screen, and moves right into the player, no time or distance so I blow my whistle and call a moving screen. I know it is a foul and I probably should call a block, but is it possible for a defensive player to set a moving screen?

I hope I am clear....