Has no one thought of this? (spoiler). My theory.

It seemed to me that the guy was not all that injured in the car accident. Just his head. However he starts to cough up blood and pee blood. Also they mention that he got kicked out of his apartment. My theory is this, he didnt get kicked out. He is dying. He is leaving school forever and he decides that since he is dying he throws caution to the wind and get this girl alone for the last moments he has. He wants to spend his last moments with her so he never really tries to get help. He is able to help her as a ghost because he wasnt killed by the cop. He mentions that their are two kinds of re-incarnation. One type you come back as someone else, the other you just keep living the same life over and over. Im guessing that means the cop. Anyone else wonder this?