Bunting/offering at the ball

Question
The opposing batter pivoted to a bunt position with the bat extended out over the plate during the pitcher's delivery.  The ball sailed over the batter's head and hit the backstop.  The umpire called it a ball.  The batter then pulled the bat up to her shoulder in preparation for the next pitch.  I requested time and then spoke to the umpire who stated that despite the bat being extended across the plate while in a bunting position, the batter had not moved the bat and so no offer was made at the ball.  I refrain from striking the umpire to prevent setting a bad example for my players.  This umpire is our umpire in charge and, while I have no recourse over last night's game, I want to clarify this matter for the future.  What definitive source of umpire rule interpretation exists?

Answer
Hi Greg,

I'm really glad you controlled yourself so as not to set a bad example for your players......you'll be glad you did the same as you could have really embarrassed yourself in front of the kids when you read this and find out the umpire was absolutely correct and you were wrong.

POE 10 2007 ASA umpire rulebook "On a bunt attempt where the batter puts the bat across the plate and the pitched ball is out of the strike zone, a ball should be called unless the batter moves the bat toward the ball."

Your umpire knows the rules it seems to me.

Mark