Was there an officer that worked the accident? the accident should have been ruled a "no fault" which basically means no one is at fault, But in this case it sounds like the fault lays evenly on both parties because neither one of them we're legal to be on the road, Since neither party had insurance. So he should only be liable for his bills and not the other vehicle. Howevwer it is very possible that he can be sued for his bills that he is liable for. The only other option is for him to plead his case to the medical director of the hospital and see if they will accept a reduced payment, a payment plan or even right the bills off as charity. I know it sounds bizarre but I know of a few cases from a hospital in north east arkansas, where I live, that has done that for families that could not pay their bill.
Best of luck.