Hardware

The user should save her documents. If she is too lazy, or does not know how, she should ask. Just walking away does not impart responsiblilty on the tech. It really kind of looks like some kind of booby trap.

Make them shutdown all their programs and save as needed while in front of you.

I'll always close their apps and if it prompts me to save, save them back to the default location as same filename-v1 - that way they have the file if they need it and they can delete the extra copy if they don't. I suppose that yes you could say it's their responsibility since it's their work, but equally it's a tech's responsibility to make sure the work they do on a machine doesn't cause data loss for someone.