Car Accident/Auto Insurance....

My son had a fender bender yesterday afternoon on Lake Miriam...he was hit from behind and my older car, that he drives, has damage to the trunk, the bumper will need to be replaced and the taillight as well.  The guy that hit him got a ticket for either careless driving or following too closely, but either way, he was ticketed.  I called his insurance company today, after speaking to mine, and the girl took all of the information, and then says to me, "I will be in touch with your son for his statement, and then I will be in touch with our insured for his statement, and to see if he accepts responsibility for this accident."  WHAT???  I said to her, as calmly as I could, "He got a ticket...doesn't that make him responsible for this accident?"  So she said she would be back in touch with me as soon as she made contact with everyone involved.  HOW can he NOT accept responsibility if HE GOT A TICKET?  His insurance company is USAA....she gave me repair shop information, and said they will do a "courtesy" estimate but IF HER INSURED DOES NOT ACCEPT RESPONSIBILITY FOR THE ACCIDENT, then it is just a "courtesy" estimate.  Anybody have any experience with this, even AFTER the other driver was ticketed?  Thanks.....