Can you file a police report after you leave the incident? - 1

Hours after a parking lot fender bender this kid called and said he filed a police report about it? I thought it was a general agreement that you have to do all of that and call your insurance when the scene happened. Also has he contacted his insurance yet? If he did then i would've been notified immediately from my insurance correct? The incident was i was backing up after looking both ways and slowly backed out, he hit my car coming through the lane and has two dents and long scrapes all over his car, which shows he didn't stop and wasn't pay attention or was speeding, i also have two witnesses that saw this and can confirm he was speeding. Also he had his iphone on the seat next to him as i asked him so i can have his phone records checked if necessary to see if he was talking or texting at that time. Also because the dents aren't big it shows that i wasn't backing up fast when it happened also.

You have a certain amount of time before evidence would not exist to file, and in this case a couple days isn't too late.

The kid has probably not been in an accident and wasn't sure how to handle it. But he must have been confident he wasn't in the wrong.

Sorry to tell you this, but you backed up when it wasn't safe to do so. You're at fault. The backing driver always has the greater duty to yield to forward moving vehicles. You're the one who needs to phone your insurance, and you're the one who should be worried about having your phone records checked.
He has the right of way. You can never impede the right of way of another driver, regardless of how inattentive you feel they were.

And yes, a police report can be filed at any time after the accident with or without your presence or permission. He obviously realized he was not at fault.