HAS THIS HAPPENED TO YOU BEFORE?

okay on Saturday my friend got into a little incident when he was backing up he turned and the back of his car swiped the other car because they were parked out farther than they should have been and then he got out and they had like a few scratches on the back they took his name and license number and the name of the insurance and they left...now they want to file a claim with the insurance..my thing is someone told me that if you dont call the police and no police report was filed nothing can happen now... and when he was telling me what happened he said they were asking him all kinds of unnecessary questions and stuff and saying how he was a new driver n etc. he said it seemed they were just out for money...what can happen to him now? oh yeah this happened in Ohio but he lives in Indiana now but was here visiting