"free" throws

[John Chladek]

How much arm/hand movement by the defense should refs allow during free throws? I know we all coach the players to have their arms/hands up, ready to rebound, but some are obviously doing things solely to distract the shooter. Last Saturday in a girls HS playoff game, whenever team A was shooting free throws, B1 would line up in the last spot on the lane (4th position?), extend her outside (away from the basket, closest to the shooter) hand as far as she could and wiggle her fingers during the free throw, even during the 1st FT of 2. Seemed kind of bush league, and I was surprised a ref didn't tell her to cool it. And what is the penalty if this isn't allowed, a warning and then a technical? Or does A1 just get the free throw over if she misses?