California Code, Labor Code - LAB § 4068

(a) Upon determining that a treating physician's report contains opinions that are the result of conjecture, are not supported by adequate evidence, or that indicate bias, the appeals board shall so notify the administrative director in writing in a manner he or she has specified.

(b) If the administrative director believes that any treating physician's reports show a pattern of unsupported opinions, he or she shall notify in writing the physician's applicable licensing body of his or her findings.