The cops are the ones investigating, and I'm sure the number of actually stolen rental cars is far greater and comes along with identity theft. But at Hertz some human should do a thorough check.
The Australian solution to Hertz is give out company fines until they produce who did the false report.
No need to go after the CEO or related. It's not like Hertz is suddenly going bankrupt to dodge the pitful fines.
If the potential damage is more than the company can afford, then by all means, they should go after those running the company.