After hearing gunshots, the janitor, his wife and a kid run down the hall and open the door to the apartment. The scene changes to show them from inside the apartment, looking in, but the hallway they came from is gone, replaced by a light colored wall right behind them.
Peter Gunn and the janitor are standing outside the janitor's apartment. The janitor shows where the shooting happened by pointing more or less across the hall. He should have turned and pointed down the hall to the right.