I used to work with an operator who told me that at his previous employer (large commercial printer), every job had to be signed off on before it could be run. One sales rep's answer to that would be to sign-off on a BLANK SHEET before the job was on press, and after the operator was up to color on the job he would send that sheet through the press, and that would become his sign-off.
The operator explained it as the sales rep's extreme confidence in his ability to produce quality work. I think it's possible that the sales rep may have had 'more important' things to do.