Sadly the practicing side and the regulatory side are different enough that I basically don't have much insight into why my views are wrong. (I mean, presumably if my views were right, some enterprising lawyer would have applied the theory already.) E.g., if there is legislation that is acting as a barrier, we could get our representatives to change it. If these folks remain boarded and are practicing outside of the norms and scope, then we could get our medical licensing boards to take action as well.
They get access to whatever records transmit to the insurance company and they provide a medical opinion on the necessity and adherence to accepted standards of care of given treatments.
That's not the same as what doctors and nurses do.
They get a bunch of test results and a first opinion (from doctor) then they issue a new (second) opinion of no treatment. Doctors give out second opinions all the time; it's a thing patients do when they want to make sure the first one is correct.
Doctors and medical reviewers are looking at the world through two different perspectives.
Doctors have direct contact with the patient and are pursuing leads via testing and originating a treatment plan.
Ergo, "what might work"
A medical reviewer is limited to generated documentation only (though can request more) and is then comparing that to relevant regulations, standards of care, and reasonable/necessary tests.
Additionally, they are a technical expert in recognizing fraud that may be hidden in individually-reasonable, unreasonable-in-aggregate cases.
Generally, criminalizing malpractice is a counter-inventive to actual system improvement. See doctors. They just add malpractice insurance, and the cost is added to everyone.
If the real concern is that medical reviewers aren't fairly reviewing claims (which afaik, they generally are, contingent on documentation being available), then the supply side should be addressed -- mandate a specific, minimum review time per claim, a standard appeals chain that all insurers are subject to, and staff a centralized, independent (probably under CMS) final appeal arbiter.
The concern for me is that they have a perverse incentive. They aren't interested in maximizing the effectiveness of the care I receive, they are interested in minimizing their own costs. They should be held legally accountable for any negative effects their input has on me.