Traffic accident in Ireland: advise is needed

Hi, we travelled to Dublin from Belfast. Upon exiting from the filling station (and prior to joining the actual motorway) we got hit by the car, my parent requiring to go to hospital with suspected neck injuries. I was approached by a witness (of which I tool a verbal statement), took photos of the damage to vehicles and the registration details. I could not wait for Garda as we left in the ambulance to go to the hospital. The car was subsequently towed away in our absence.

Now, I reported this to my insurance. My next step, as I understand, is to make a witness statement with Garda. Next, is to ask the witness to the same in the local station. I do not know the insurance particulars of that person, nor the name. I just assume she was the owner due to seriousness of injuries and the need to get to the hospital. Can you please suggest how to approach this puzzle?

PS My parents are dependent family members of an EEA citizen residing in UK. Will they be billed for hospital admission in Ireland?

Thank you