Hire Car Hiccup

My mum hired a car last week to visit us & had a couple of hiccups. Firstly on her journey through the peage the chap in front decided not to use his handbrake and as he bent out of his car to take his ticket his car rolled back (way back!) and touched her hire car. Luckily no damage was done to her car (his had a little dent but he shrugged and got back in - no problem).

The week went by sans probleme (I drove us around as she’s not overly confident when I’m in the car) then she returned the hire car to the airport & unfortunately touched the side of a Hertz car with her wing mirror on parking. Her car again had no damage but the Hertz car has a scratch which was witnessed by the Hertz staff who filled out an incident form

The rep for her car company didn’t show up at the airport so the Hertz people wrote up the report and confirmed her car was not damaged. We’re now not sure what is going to happen & wondered if anyone has any experience of this?

If you damage another vehicle but your hire car is not damaged do you lose your huge excess or does the insurance you paid for cover the damage to the other vehicle?

She’s not sleeping well at the moment waiting to hear from the hire car company or her credit card company about whether they’ve taken/are taking an 800 euro excess of her for a tiny scratch!