In a lot of these cases one of the major problems is that many debilitating disorders and syndromes are beyond current means of objective testing. The insurance docs, such as CIGNA's, use this fact to claim that there is no evidence of disability, when in reality the level of evidence they want is unattainable with current medical technology.
In this case, the judge decided that this wasn't good enough for CIGNA to deny benefits and that the overwhelming record from the treating physicians was more than enough to justify benefits despite that much of it was based on "self-reports" from the plaintiff. This a great ruling in that it basically recognizes the impossibility of attaining a certain level of proof that insurance claim as necessary for granting benefits.
Read more, including entire opinion on Toth v. INA, on how treating physicians opinions can hold more weight than insurance doctors.