Whether AIR 21's affirmative defense is satisfied where an employer proves protected activity played only a limited role along with non-protected conduct in an adverse personnel action

The Question Presented is: Whether AIR 21’s affirmative defense is satisfied where an employer proves protected activity played only a limited role along with non -protected conduct in an adverse personnel action, instead of proving the employee was not treated worse because of the p rotected conduct. The Federal Railroad Safety Act ’s (FRSA) whistleblower provision expressly incorporates the two-part burden -shifting framework of the Wendell H. Ford Aviation Investment Act for the 21st Century (AIR 21) in providing, “[a]ny action brought under (d)(1) shall be governed by the legal burdens of proof set forth in section 42121(b).” 49 U.S.C. § 20109(d)( 2)(A)(i). Under the AIR 21 framework, an employer violates the law if an employee demonstrates that protected conduct “was a contributing factor in the unfavorable personnel action alleged in the complaint.” 49 U.S.C. § A court may not order relief “if the employer demonstrates by clear and convincing evidence that the employer would have taken the same unfavorable personnel action in the absence of that [protected conduct].” 49 U.S.C. § 42121(b)(2)( B)(iv). In Murray v. UBS Securities, LLC , 601 U.S. 23, 28 (2024) this Court confirmed , “[t]he framework was meant to relieve whistleblowing employees of the excessively heavy burden under then -existing law of showing that their protected activity was a ii significant, motivating, substantial, or predominant factor in the adverse personnel action, and it reflected a determination that [w]histleblowing should never be a factor that contributes in any way to an adverse personnel action.” (internal quotation marks omitted).