Backing up Ouch!

[oneworld]

Yesterday I pulled up behind a car parked in front of a building. While I went in to pick up a key a guy making a food delivery in a small old honda civic pulled up behind me. It was puring rain and dark. The honda pulled up a little close to my bumper and had no lights on.
Long story short > I did not notice his car when I got in mine to leave > and so I had to back up to clear the car in front of me. I looked in the mirror and saw nothing. But reverse hit something > my 5th wheel and rear recovery hook left two nice big dents in the top of his hood > Ouch $250.00 we settled it right their, No damage or scratches to My H3. You cant see low cars at all behind you if they are close so be careful. I usaly open my driver door when paralel parking backing up.