Driver saw me and drove away

I use Uber/Lyft a lot, often taking the pool or line to work.  Uber has recently given me a 30% discount up to $6.00 on Uber X which means that it's often cheaper than pool.    I live in the DC area and my commute is about four miles.    I have a 4.9 rating.  This morning something happened to me that was very odd.  I called an Uber X and it showed arrival in 2 minutes.    I saw the driver arrive in front of my house stop the car, I opened my front door and began to walk out, the driver looked right at me and started to drive away.  The app indicated that I was on the trip, when clearly I was not and then the driver cancelled a few seconds later. I had to call another Uber and by that time the price had increased and I had to wait another 5 minutes.   I have never had this happen before.  The driver looked right at me, I live in a residential area, it was not busy and there was no way there could be any confusion.    I reported to Uber.    I did not have heavy bags, luggage, I did not have any animals with me.    I am a well dressed professional business woman.  Why would this happen?      Has this happened to anyone before?  I did not get charged the fee so clearly he took the hit on it.