Gunderson v. United States Department of Labor

Even though intimately familiar with the issues and knowledgeable as to the scientific principles presented in a case, an administrative law judge (ALJ) is not an expert. The ALJ is not expected, nor permitted, to meld expert opinion into his own unified theory, which he then independently applies to the facts. And it is beyond the ken of an ALJ to resolve a scientific debate. Instead, once the ALJ determines “an expert’s testimony both rests on a reliable foundation and is relevant to the task at hand,”1 the only issue *1028is credibility. When expert opinion is diametrically opposed, the ALJ…