The ASA rule says the batter shall not 
"Interfere with a play at home plate." It does not say the batter is required to vacate the batter's box during a play or pending play at the plate. POE 32 adds that the batter's box is not a sanctuary, but, still, does not 
require the batter to vacate the box; it only requires the batter to not interfere.
A key comment in your situation was 
	Quote:
	
	
		| receives throw from catcher, but it is not in time | 
	
 This doesn't sound to me like the batter interfered 
with a play.
No play, no interference.
To your larger point, though, early in the season, I teach players and coaches at this age.  Later in the season and/or in tournaments, I call it 
if, in fact, it is interference.
[Edited by Dakota on May 30th, 2003 at 01:57 PM]