Now that it looks like everyone agrees, this foul needs to be called let me tell you this story.
A regular partner of mine was doing a BV scrimmage last week and had this very call. He watched the shooter down, the block-out displaced and he called the foul. The 3-pointer was good and the team got the ball back for a throw-in.
After reporting the foul, the offended coach and host of the scrimmage said, "you better not call that in a varsity game."
Apparently all coaches don't agree with us. Wait, I already knew that.