Hit-and-run?

Hello, was just with dogs gassi, then I saw the parking of a pensioner. Well… he just had to drive in backwards. There was only a VW and Renter drove a Opel. Well…Rentner drives backwards and “pushes” the VW…. VW was probably hit more at the license plate. I was at the height of both weighings than I saw that, on the other side of the road. Pensioner got out, looked fleetingly after his car and left. I then returned. Visually nothing was visible at the VW. I went my way. e gassi round on. When I went back, the Opel was gone. There was no note on the VW. I noted both car numbers and time in the mobile phone. Should I forget it? Or should I report it to the police for a moment? I’m really unreliable…..war only the typical door in the parking lot….but so could for example a bracket in the inside be broken and spare parts at VW are known to be not cheap…. Your opinions on this? Thank you, Jürgen