Been there, done that, never gonna do it again.
I drive a P7 with barn doors, so if I am done at a dock stop I have to pull forward a couple feet with the back doors still open and then walk back to shut them. One time as I was pulling forward the shipping clerk came running out and asked me if I could come back in 20 minutes for a few more packages. This distracted me, and after talking to the shipping clerk I forgot to get out and shut the back doors and I wound up driving half a mile to my next stop with both of them wide open. Didn't lose any packages but it scared the hell out of me so now I have a system;
if for any reason I am moving the car with the back doors open, I make sure to have the bulkhead door open also. I can easily see the open BH door with my peripheral vision and it serves as a perfect reminder and makes for a good routine.
It also causes me to show up on a Telematics report, which I could care less about, but once during an OJS I had a rookie supervisor bark at me about it and order me to stop doing it. I told him it was a safety issue and that I would continue doing it whether he approved or not. He threatened to discipline me for it, and I told him to go right ahead. He puffed his little chest out and marched off to the center manager's office with an anger boner, all ready to write me up, until my center manager (who was a good one) told him to find something important to worry about.