On the subway platform, the police officer shoots Oscar in the lower spine. But when the paramedics examine him, a bullet wound is visible (and treated by them) on his chest near the shoulder, and later at the hospital, surgeons remove the bullet there as well.
When Oscar drops his daughter off at daycare, he has to knock on the door to enter with her. When he picks her up later, he walks up the side driveway, enters the back yard and starts playing with her. No one really acknowledges him.