Need Confirmation (or clarification)

[Bassman]

OK here's the situation:

In NFBR game Thursday night, R1 was on first. Pitcher was in the stretch, attempted a pickoff throw to first, and overthrew. My partner initially awarded R1 third. HOWEVER!!! Since the pitcher's pivot foot was still in contact with the rubber when he made the throw, I conferred with him and R1 was sent back to second. R1's coach went postal and insisted that his runner gets third. His reason? He thought that since the pitcher didn't commit to the plate, the pitcher balked. (go figure coaches don't know the rules).

Thoughts?