> I immediately filed a complaint with the insurance company's California regulator (at the time it was the Dept of Insurance for this one, but it seems most or all now are under the Department of Managed Health Care) since insurance companies are by law obligated to pay at the in-network rate in the case of an emergency (which presumably is why you call an ambulance in the first place). Within 2 weeks I received a letter from the insurance company that all was completely fine and that they'd corrected the situation and paid the bill.

First: Hats off -- nice work.

What annoys me the most about this story: There should be a disportionately large penalty that the insurance must pay to the health care regulator for cases like this. It would discourage this kind of illegal behaviour.