The use held down the SHIFT KEY during the procedure which means MOVE rather than copy.
It was an honest mistake.
I have a reason to believe a Windows document folder was cut/taken from my laptop. There was a block of time when someone could had stuck a thumb drive in my laptop. Paranoid? Maybe. The folder that was in C:\Users\MyName\Documents has completely vanished. Not in the recycle bin, not anywhere else on my C: drive. I back up weekly, but unfortunately lost an important week's worth of work. Any ideas on how/where to find the folder?
BTW, I will now be backing up daily!