In basketball, it is not a violation if a player fumbles the ball and then recovers it, as long as they do not start a new controlled dribble. Hence, the official is incorrect in ruling it a violation.
In a game of basketball, once a player ends a dribble and picks up the ball, that player is not allowed to restart a new dribble. A player is allowed however to run and recover the ball if it's fumbled unintentionally. Therefore, if A-1 merely fumbled the ball, not purposely resuming a controlled dribble, then the official is incorrect to rule this a violation.
Learn more about Basketball Rules