We had a driver receive a similar concern yesterday. Customer complained that the driver did not bother to knock on her door while making what I believe was a second delivery attempt on her package. The 1-800 customer service person coded it as an hourly personnel, what we used to call a rude hourly. These have to be addressed within one hour of receipt. Our on car sent an ODS to the driver asking if he remembered the stop and, if so, whether he knocked or not. I don't know if they checked his GPS to see if was there and, if he was, how long he was there. I am pretty sure if GPS supports our driver the rude hourly will be thrown out.
I can only imagine what would have happened had the driver decided to do what you did and call the customer a liar.
You were way out of line.