Pitch - Illegal or No Pitch?

[Duke]

Had a fellow blue call me with the following situation that happened at a ASA 14U Tourney this past weekend while he was calling the plate.

Runners on 1st and 3rd. Coach calls time to confer with his batter and base runners. Play is set, as the pitcher goes into her windup the batter steps out of the box causing the pitcher to stop in mid pitch. Fellow blue calls "No Pitch" and resets. 3rd base coach goes ballistic saying his runner should advance to home on the illegal pitch. After much "conversation" the original call stands.
I told him he made the proper call and refer to rule 6-10E.
The case book has a simular ruling under 6F.10-2.
Your thoughts?