Should require re-insurance for companies that self-insure

I had a friend whose employer went bankrupt in the midst of a family member undergoing surgery. Because the employer self-insured, he got stuck with the bill when they went bankrupt. This just seems wrong to me. Maybe companies that self-insure should have to have some form of re-insurance as a backstop. Or, alternatively, healthcare providers that accept third-party payment  should indemnify their patients in the event the paying party goes bankrupt.