well, I didn’t say “criminally”. Held responsible criminally for a violation of law would presumably be the driver. But assuming we are talking about a US case (where anyone can sue anyone and everyone in civil court): there is coverage for the damage to the rental vehicle and also liability for other damage and injuries/deaths.

For liability for US rentals, I use my personal vehicle liability insurance. For vehicle damage I use my CSR credit card coverage.

Is my personal liability insurance going to cover a stranger (valet) who is not on the rental contract driving my car? Does the valet company have sufficient liability coverage? Does the hotel’s insurance cover it?

Is CSR going to cover damage caused by a stranger (valet) who is not the renter or explicitly authorized driver per rental agreement. Or, as in the OP’s case, will Hertz consider it a violation of CDW terms to let an unauthorized driver park the car? What does the renter’s contract with the valet company say? I could imagine they have some “we are not responsible for nothing…” disclaimers posted or in 2 point font on the valet ticket, whether enforceable or not.