To be clear though, I doubt that someone in Hertz management sat down and devised this scenario deliberately to save a few bucks, hoping that nobody with social media clout would ever run into it. My guess is that it's the result of a web of misaligned incentives and organizational cruft that resulted in a creaky but mostly-working system that nobody ever fixed.

You can use your imagination to fill in the details for fun - maybe 8 years ago some stressed-out shift manager without enough people to work the rental desk (due to a freak corporate-mandated hiring freeze) got a call asking for updated contact information for his location and he hesitated a moment and the caller, a temp on loan for the day, helpfully suggested that they just leave the extension blank for now, and marked the location done. And over the next 8 years the company was making its numbers and there was no need to rock the boat and dump a bunch of money into management consultants to tear everything up and start over fresh, and the VP of airports just had a grandkid and was letting his lieutenants run things on autopilot, and the CEO was happy as a clam with his 2pm golf games and expensed steak dinners and had no idea that anything was wrong, etc etc etc etc. The WSJ exposé following Hertz's surprise Chapter 11 filing practically writes itself.