Had a weird experience this past weekend with Dollar, and was just looking for an explanation...

My rental was originally with Enterprise, but when I got there, they informed me that they were completely out of cars. No big deal, they sent me next door to Dollar and made sure that they had cars available at a similiar rate to Enterprise, which of course they did. While going through the paperwork, the Dollar agent explained that since I had been sent over from another company, that regardless of what happened to the car, I would not have any liability whatsoever (and no I didnt have to pay or sign for any of those damage waivers), and all that would be on Dollar's shoulders should something happen to the car.

Of course, nothing happened and the rest of the rental was very smooth, but my question is, what's the rationale behind Dollar accepting all liability simply because I was sent over from a sold out company???

Thanks in advance!