(e) In any civil action or administrative proceeding, once it has been demonstrated by a preponderance of evidence that an activity protected by this article was a contributing factor in the alleged retaliation against a former, current, or prospective public school employee, the burden of proof shall be on the supervisor, school administrator, or public school employer to demonstrate by clear and convincing evidence that the alleged action would have occurred for legitimate, independent reasons even if the public school employee had not engaged in protected disclosures or refused an illegal order.
If the supervisor, school administrator, or public school employer fails to meet this burden of proof in an adverse action against the public school employee in any administrative review, challenge, or adjudication in which retaliation has been demonstrated to be a contributing factor, the public school employee shall have a complete affirmative defense in the adverse action.