What if he didn't die? [SPOILER]
So #13 got shot several times and was left to die. By the time the scene changes, he has fallen to the floor and is too weak to move. But we don't actually see him die, we just assume it.
Personally, after all he went through against his will, I choose to believe that someone finds him before it's too late, calls 911 and he survives. As for the shooter, he believes that #13 died on the train and will not be looking for him.