ASA - erasing a line

[Andy]

Situation presented to me by a friend.

ASA Men's SP - PU (my friend) calls a batter out for having one foot completely out of the batter's box when he contacts the ball. Next batter steps into the box and begins erasing the front batter's box line with his foot. PU calls a penalty strike. After the game, he looks in the ASA book and does not find a rule that allows a strike to be called for this specific action, unlike the NFHS and NCAA rulings.

I advise him that since the actions of the batter (erasing the line) is most likely due to the batter not liking the out call on the previous batter, his action of erasing the line could be considered unsportsman like conduct. PU should warn the batter to stop or be subject to ejection. I don't know that I like this option, but at the same time, the batter's actions are intended to "show up" the umpire and probably need to be addressed.

Your thoughts and/or comments?