[PeteBooth]

Originally posted by Lilblue612

Working the bases in a game played under Fed rules, the batter (with no outs and no runners on base) hits a ground ball between the first baseman and pitcher. My partner behind the plate, reacting to the sound of the ball hitting the bat, quickly calls a foul ball. However, he is suprised that despite the sound, the ball was obviously fair. Yet, because he had called "FOUL" so loudly, the batter-runner instantly returned to the plate. Thus, the defense easily retires the batter-runner at first. In discussion, my partner and I wondered if the play should stand, or if his accidental, incorrect calling of "foul" should allow the batter a fair (no pun intended) chance.

The applicable rule for FED is rule 10-2-3L
The UIC shall rectify any situation in which an umpire's decision that was REVERSED has placed either team at a disadvantage.

When B1 reacted to the call of FOUL (he returned to the plate), you CANNOT change to Fair because that would put the offense at a disadvantage.

Pete Booth