That's a crazy story. I can't believe you didn't feel that civic though hahaI had something like this happen with my Jeep and a little Honda. I stopped in a parking lot at the mall to let my wife out. I was just going to wait for her in the Jeep. This little Honda Civic go up behind me while I was using my phone and I didn't know he was there. Someone asked me to backup so they could pull out of a spot. I looked out the back window and checked the mirrors, didn't see anything and started to back up.
I heard someone blowing a horn like crazy, so I stopped. I looked everywhere and still saw nothing. So, I started backing up again and again, I heard a horn blowing. I stopped, got out of the Jeep, and there was a little Civic half under my Jeep. I had pushed the car about 40 feet and had zero clue it was even there. Needless to say, the people in the Honda were not happy.
I can understand not knowing you had impact... cuz I had no idea.