If you get an obvious sign that a valet worker does not know what they are doing, what should you do?
In this situation, even though it may not be convenient, you have to either summon for the manager and get assurances that the rookie won't touch your car, or just leave.
Frankly, I think it is a clear sign of managerial incompetence to deploy a bewildered, brand new rookie valet, who can't talk, into a position where he suddenly is in control of expensive automobiles. I would not have faith in that manager's ability to keep your car unharmed.
There is a way to flush out rookies and get the car into the care of more experienced valet workers. You can read about it in my six-part series "The Smart Way To Use Valet Parking Services."