If you’re putting grocery from a shopping cart into a car trunk and it rolls into a passing car, who is going to pay?

My daughter has a man demanding she pay for slight damage to a Limo driver whose side door got bumped with a grocery cart while loading her infant and groceries. She said that I will pay. He didn't insist on a police report but now he came in with a high estimate for repairs. He saw it was windy and she panicked to chase the cart. She's newly widowed and not working. She doesn't feel that she should have offered anything and allowed a police report.