Funny, I was actually thinking about that nuance just earlier today because I myself know that physicians and their offices have been, with increasing frequency, billing for services not rendered. If insurance companies actually compensated the physicians fairly (rather than keeping the compensation identical to or les than it was decades ago - you read that right!) then this type of fraud wouldn't occur nearly as much. They're preventing physicians from earning even inflation-adjusted amounts for the same services. It's terrible.
Now, regarding actual errors from the physician side - definitely, those do exist and should be caught and punished appropriately. However, I'm yet to hear of an insurance company preventing a medical error lol! It seems that more damage comes from physicians not being able to practice the way they should, and instead conforming to the restrictions placed by insurance companies.
I would be interested to find out the motive once this killer is caught. At least one positive thing came out of this: executives might now become a little bit more fearful of denying at such extreme rates that UnitedHealthcare has been doing (approximately 1/3 of claims!).