hyundai accent 1.5 turbo

Hi, I wonder if this is the appropriate section or even the right forum to post this. Need some help from those with experience in accident cases.

Are all accidents even a very minor one need to be reported? I had a minor accident this morning while turning into another lane and this car knocked my rear bumper (on bumper corner). The driver said forget it. So, should I report or not? If don't, what if he eventually go to make a police report?

Only scratches found on both cars. Am I at...