What is the significance of the scene with the young boy soldier?

When Pfefferberg shows up and knocks on Schindler's glass door, he tells Schindler that that he has new about Stern. Schindler then heads toward the train headed to Auschwitz at the station and approaches a young soldier with the list of Jews on the train. The man tells him that Itzhak Stern is, in fact, on the list.

Schindler removes a pad from his pocket and begins to take down the man's name when a young officer approaches. He tells Schindler that the list is always correct, and Stern must not be an essential worker. Schindler also takes down the officer's name before telling the two men that he can guarantee that they will both be in southern Russia by the end of the month. The young man with the list makes the conductor stop the train, and Stern is removed safely. He walks with Schindler and apologizes for forgetting his work card at home.

This scene is significant because Schindler's ability to remove Stern from the train to Auschwitz evidence of his growing power.