In play or out of play

[PP]

A1 and B1 are running for a loose ball near the sideline. A1 being the faster player touches the ball and then dribbles but his momentum carries him out of bounds because he is off balance. The ball is still inbounds near the sideline. A1 then returns inbounds to secure the ball and continues his dribble. The official ruled that A1 is not allowed to secure the ball once he goes out of bounds and then comes back inbounds. Is the official correct?