Nothing will come of it. It would be too costly for them to take him to court and they would end up losing money at that point. Like mentioned, you can't actually face jail time for such thing. Since the debt isn't massive, they will likely just pester him for a few years and it will be dropped after 7. I know it can be scary when they threaten you but they just want their money, that is all.
From what I was told, if it totals over 30 grand, they are likely to take it to court to try and get something out of you but from what I read online, they don't seem to bother with debts unless they are well over 50 grand. I think it really depends on the hospital and the state. I have a friend who owes 60 something thousand from a car accident. She was in the hospital for 8 days without insurance. She has not paid a dime on it and it has been 3 years, nothing have come of it yet.