5 CFR 1209.7: Burden and degree of proof.

(a) Subject to the exception stated in paragraph (b) of this section, in any case involving a prohibited personnel practice described in 5 U.S.C. 2302(b)(8) or (b)(9)(A)(i), (B), (C), or (D), the Board will order appropriate corrective action if the appellant shows by a preponderance of the evidence that the disclosure or other protected activity was a contributing factor in the personnel action that was threatened, proposed, taken, or not taken against the appellant.

(b) However, even where the appellant meets the burden stated in paragraph (a) of this section, the Board will not order corrective action if the agency shows by clear and convincing evidence that it would have threatened, proposed, taken, or not taken the same personnel action in the absence of the disclosure or other protected activity.