I lightly bumped against someone’s car while exiting a parking lot. There was no one inside.

I waited next to the car for the owner to show up. We agreed on me paying him $120 and we both left. I left the area for about 30 minutes and came back later, did’t see the car still there so I assume he left as well. We didn’t exchange contact information so i doubt he knows who I am, and i doubt he hid to follow me to my car. But since we didnt exchange any information and didnt do this through insurance, how safe am i? I paid in cash to avoid getting insurance involved but since nothing was documented, am i legally screwed? What are the chances im served letters within the following weeks? If that is a possibility, is there a way i can pay again (if i was finessed) in cash, this time with everything documented, so that i could avoid filing a report to the local PD, DMV, and my insurance?

Edit:
I want to add if this counts as a hit and run as well, but im assuming not since I’m pretty sure i did my due diligence in trying to settle this. Additionally, i moved to a different part of the parking lot then went back to (what I am pretty sure was the car) and waited for the owner. Should the possibility that it wasnt a) the car and b) the owner, could this be seen as a misunderstanding rather than a hit and run?