After nearly getting hit by someone the other day I end up doing essentially the same thing, after an awful, tired, and grumpy morning. I was waiting to pull out of the parking lot I was in for over a minute and there was a pedestrian coming. While I had been waiting I was repeatedly checking my centre mirror for any cars behind me, and to my surprie there were no cars. I did not check again when the pedestrian came and I believe I tapped the car behind me. I got out and looked for damage, and there was no sign of contact, so I asked if we were good, and the lady driving the car looked a bit confused and said yeah (I'm honestly not entirely sure I actually made contact, I was pretty damn tired and brain no work good when tired (may have been bump on road that stopped me?)), so I guess it was ok. brb, killing myself.