When does girl have to return to the bag?

Question
Situation:  Runner on 3rd base.  Batter draws the fourth ball and heads to first base.  While Batter/Runner is running to 1st base, the ball is returned to the pitcher by the catcher while in the the pitcher is in the Circle.  The Runner on third base stays about 10-15 feet away from 3rd base (towards home) waiting to see if the Batter/runner will round 1st, heading for 2nd or not.

The umpire calls the runner at third out and explains she did not return to 3rd base once the ball was returned to the pitcher in the circle.

As the coach, I argue that the runner on third does not need to return to third base until the batter/runner has reached 1st base.  IE, runner on third has the right to stay off the bag until the play completes (by batter/runner reaching 1st).

The umpire actually reversed the call and let the runner on third return to the base safely.  YET, afterwards I question my own explanation and wonder:

"When does the runner on third become compelled to return third?"  1) Once the ball is in the pitcher's control while in the circle, no matter where the batter/runner is?  OR 2)  Only after the batter/runner has reached 1st base?

Your help is appreciated.

Thanx

-Jason

Answer
Hi Jason,
Thank you for your question, and for the appreciation in advance.  Your Look Back question is NFHS Rule 8-7 and ASA Rule 8-7-T.  Your play concluded, for the most part, in a satisfactory manner, in that 1) the runner who was on 3B was allowed to remain there, 2) the out was reversed, and 3) the batter/runner reached 1B.  It is a credit to your look back rule knowledge that you approached the umpire about the call and a credit to the umpire that he reversed his incorrect call.

The look back rule goes into effect when:
1) the ball is live
2) the batter/runner has reached 1B OR has been put out
3) the pitcher has possession/control of the ball within the pitcher's circle

So, the runner who was between 3B and HP should not have been called out, as the b/r hadn't yet reached 1B.  After the ball reached the circle, she wasn't required to return to 3B, either; she could have advanced to HP.

Now I can elaborate on why I said that your play concluded only mostly satisfactorily.  A look back out is a no pitch/dead ball out.  You didn't mention whether or not the umpire ruled a dead ball when he called out the runner who was on 3B, but he should have.  Unfortunately, though, "killing" the ball when it should have remained live "killed" the defense's opportunity to get two more outs AND the offense's opportunity to score two more runs.

Scott Kelly