“Cockerill’s insurer said the car wasn’t in her control, so it shouldn’t be her problem.”
WRONG...
She is responsible for the car until the location opens, as stated in the rental agreement.
The company has a system whereby the renter can drop off the car. It is their system made available to their customers by them. They can shove the bill you know where.
That's not entirely clear here as many contracts contain onerous and unenforceable clauses, or what the ramifications are of the Company making it's lot available and providing a drop box for the keys. Point is again, it's not cut and dry as you think it appears.
“WRONG...”
Not necessarily. Simply because the woman in question signed a contract with those terms does not mean that those terms apply.
Contracts are not in and of themselves law, it’s not possible for parties to a contract to lawfully agree to disregard the law. A contract is not legally binding unless the terms and conditions of the contract also fully adhere to the law.
As an example, if the courts hold or have held that a reasonable person exercising reasonable caution cannot be held liable for a rented automobile after the customer has returned it in good condition to the rental lot, then it really wouldn’t matter what in the hell the contract spelled out.
A good argument could be made that it is the duty of the rental agency to ensure basic security on their rental lot, and that it is unreasonable to expect a customer to adopt the burden of security on the rental agency’s property, and hence that any damage or loss suffered while the auto is on the rental agency’s property is likely to be substantially the fault of the rental agency.