High School game, Runner on 2B. Batter takes 4th Ball for a Walk and starts out of the box to head to 1B. Catcher catches 4th ball and immediately comes out from behind home plate to throw to 2B to pick at Runner. There is no contact made however the umpire calls the Batter out for Interference with the throw from Catcher. The throw was not impeaded in any way and was actually a good throw which did not result in an out. Where in the rules does it state that the Batter who Walks, is not entitled to run to 1B in the first place regardless of the catchers intentions?
Original Post
On the surface it sounds like a bad call, but it's one of those UMPIRE'S JUDGEMENT things. If, as you say, the batter did not interfere with the catcher's throw then it shouldn't have been called. But if the ump saw something whereby he felt the batter interfered with the catcher's throw (like the batter pausing right in front of the catcher) then the batter could be guilty as charged.