“Failure To Remain When No Damage?”

So yesterday I was taking my daughter to the walk in clinic, she was screaming. We had over an hour wait so I decided to leave and go home and get her milk and come back. While i was leaving, she was crying, I backed up and hit a car. I got out, there was no damage to either car. I went home, got her milk and went back to the doctor. The car was still there, so I checked again, and no damage. She was next to see the doctor so in we went, while we were in the room I wrote a note to the owner of the car, intending to just tell him I bumped him, no damage but here is my number. WE came out and he was gone......I called local police, they said to do nothing since the guy left? But should I still file something or just leave it? Guilt is eating me alive, even though I know there was zero damage, I was going very slow. Can I get failure to remain?

How long before I would be contacted? Do the police just call?

If the accident took place in a private parking lot, you can't be charged under the Highway Traffic Act with failing to remain. As long as the damage is under $1,000, there's no requirement to file a police report either. In future I'd make sure to at least leave a note right away regardless, but I think you've covered yourself regardless.