Georgia athletics statement provides answer on rented vehicle in crash
UGA goes on the record that the use of the vehicle was "unauthorized"
So that covers what "policy" was.
A question that remains to be answered is how closely did reality match official policy. Was "unauthorized" use truly unknown to those in charge or was it given a blind eye?
I don't know the answer to that, I'm won't even suggest what the answer is. But it's a question that will need to be answered at some point.