In this case, Getty Images provided a pretty good description of this play:
Dodger Jackie Robinson is shown crossing home plate in the 8th inning of this Dodger-Chicago game, as members of the Chicago Cubs rush in to argue with Umpire Goetz, who waved Robinson in from third thinking Cub pitcher Muncrief had balked. The Cubs claimed Furillo had stepped out of the box causing the pitcher to halt his delivery and were upheld by Umpire Reardon. Bad news for Dodger fans, Robinson was ordered back to third. But, when the game ended, it was good news for the Dodger fans with Brooklyn winning with 3-0.