FT shooter delays start of game

[Peach State Ref]

This play was posted recently on my local association's blog.

Following a 30-second timeout, A-1 is to attempt a free throw. Team A delays the resumption of play by not "breaking the huddle". The official sounds a whistle, and then puts the ball inside the semi-circle and begins the 10 second count. A-1 sprints onto the floor and enters the semicircle (prior to the 10 sec. count ending) and attempts the first of a one and one. The official rules the entering of the semi-circle a violation and administers the ball to team B put of bounds. Is the official correct?

The justification of the violation is that the ball when placed on the floor is at the disposal of the free-thrower. Please reference the rule and a case play for NFHS.