Lindsey, has he applied for Medicaid through the state he lives in? He should qualify, but he needs to APPLY NOW!!!! because medicaid can be backdated (in most of the 50 states) for ONLY 3 months. So tell him to get his butt in there NOW and they should cover the expenses for 90 days prior to his date of application. If he is "over income" for any reason, all he needs to prove is that he owes the money and he should qualify for something called a "spenddown".
I hope this helps a bit, I also agree witht he other posters that he should be dealing/harassing the insurance company, filing a complaint against whoever told him he was covered and contact the hospital and advise them of the situation.
Good luck to him,