Unfortunately, in a case like this the courts use "deferential review" as opposed to what you're implying (known as "de novo review"). The decision would be upheld for as long as the administrator can produce some evidence to support the decision, even if the decision were wrong!
> The Court's focus is upon whether the plan administrator's final decision was "arbitrary, capricious or an abuse of discretion" . Under this standard, the administrator's decision can be upheld by the Court, even if it is technically wrong, as long as there is "substantial evidence" in the administrative record to support the decision. "Substantial evidence" is a rather nebulous term, which has been defined by the appellate courts as: "such relevant evidence as a reasonable mind might accept as adequate to support a conclusion" . It does not mean a large or considerable amount of evidence. It requires "more than a scintilla, but less than a preponderance."
> The Court's focus is upon whether the plan administrator's final decision was "arbitrary, capricious or an abuse of discretion" . Under this standard, the administrator's decision can be upheld by the Court, even if it is technically wrong, as long as there is "substantial evidence" in the administrative record to support the decision. "Substantial evidence" is a rather nebulous term, which has been defined by the appellate courts as: "such relevant evidence as a reasonable mind might accept as adequate to support a conclusion" . It does not mean a large or considerable amount of evidence. It requires "more than a scintilla, but less than a preponderance."
Source: http://www.angelfire.com/biz/romarkaraoke/Defer.html
Other sources that might interest you:
[0]: http://cdn.ca9.uscourts.gov/datastore/uploads/guides/stand_o...
[1]: http://lsolum.typepad.com/legal_theory_lexicon/2006/08/stand...