Among the glider folks, there's a legend told of one competition event where the towplane was hooked-up and thought they were ready, and started the takeoff roll with nobody in the glider.
^I find such story to be unrealistic (hey, it is a "tall tale") or if it did happen they likely didn't' get very far down the runway before it was obviously a problem.... because even on a nose-hook pulling it straight: without a competent pilot at the controls the glider would quickly depart controlled flight to create a dangerous situation for the towplane (either balloon up and rise above the towplane, or dig a wing into the dirt during the takeoff roll, or nose down into the dirt).