Bill arrives and the insurer denies coverage. Provider says "oh well <shrug> you owe us $$$ now".

Since I am the resident argumentative asshole in the family I dig into the situation a bit. After many phone calls I am eventually told that the hospital routinely records all phone calls with insurance companies and furthermore has found the recording where they gave advance guarantee of coverage for the procedure.

At this point I realized we are being shaken down by a corrupt/criminal enterprise. Even with the recorded phone call the insurer refused to pay and so the patient had to pay off the $$$ over many months.