Compliant to the "better idiot theorem"
"Rather than direct the app to the folders on their desktop, they had actually directed the app to their desktop folder. The app had correctly transferred the contents to the network drive and then tidied up after itself."
This bummer could have been avoided.
Actually, the reason for the app to be written in the first place was sales users were worthless idiots.
To address that, the app had to be "idiot proof", but even so, would fall to the "better idiot theorem" which states: "Make it idiot proof and the Universe will make a better idiot". Which it did.
So, lost cause, here, change users !