timer starts clock early

[mdray]

HS sub-varsity game -- timeout with 9.9 seconds left in a 3-pt game...I had reminded the student timer during the TO to watch the official and start the clock when he dropped his arm....official hands the ball to the player, starts his throw-in count; ball is released and I notice the clock has started & the ball is still high in the air for the throw-in. I blow my whistle to stop everything...clock was down to 6.8...I told partner what had happened and we put 9.9 back on the clock and just did a do-over....thought this was the right thing to do at the moment, and reading 5-10-2 afterward, it appears to confirm this