Hopefully you got the driver's information, or at least the make, model and license number of his vehicle. In my jurisdiction it is 100% the person opening the car door into traffic that is at fault. It is a chargable traffic offense and the person responsible is civilly liable for damages they caused. That said, I don't know what the Illinois statutes are. Check into it. File a police report. Talk to a lawyer. If you want to show drivers like him to be more careful, make him pay.