Rule set was OBR, I was PU and enforced the balk, batter came back to the box. My partner told me after the game I got it wrong. Rule book confirms I was wrong - 6.02(a)Penalty.
The next pitch was a ball, so no damage done.
R1, 3-0 count on the batter, base umpire (2 man) calls “balk”, pitch sails high and wide, catcher catches the pitch, batters starts running towards first. What’s the call?