You are the chief airplane washer at the company hangar and you:
(1) Hook high pressure hose up to the soap suds machine.
(2) Turn the machine "on".
(3) Receive an important call and have to leave work to go home.
(4) As you depart for home, you yell to Don, your assistant, "Don, turn it off."
(5) Assistant Don thinks he hears, "Don't turn it off." He shrugs, and leaves the area right after you.