(b)(4) A contracting officer shall not resolve any questioned costs until the contracting officer has obtained—

(i) Adequate documentation with respect to such costs; and

(ii) The opinion of the Department of Energy's auditor on the allowability of such costs if such costs have been the subject of a DOE audit.

(5) The contracting officer shall ensure that the documentation supporting the final settlement addresses the amount of the questioned costs and the subsequent disposition of such questioned costs.

(6) The contracting officer shall ensure, to the maximum extent practicable, that the Department of Energy's auditor is afforded an opportunity to attend any negotiation or meeting with the contractor regarding a determination of allowability.