A lot of state's don't allow an employer to force an employee to pay for it, and that being the case, your "independent contractor" claim with an unlicensed teenager is going to receive extreme skepticism and scrutiny. And what does your written "contract" with your "independent contractor" say? Do you have one? Does it say anything about responsibility for damaged equipment?

And be careful you don't push the non-permissive use argument too far. You may end up with no insurance coverage for non-permissive use and a non-liable employee in a state that prohibits payroll deductions for damaged equipment.

You are in a hornet's nest of issues.