In any proceeding under subsection (b), there shall be a presumption, rebuttable only by a clear preponderance of the evidence, that the findings of fact made by the arbitrator were correct.
Payments shall be made by an employer in accordance with the determinations made under this part until the arbitrator issues a final decision with respect to the determination submitted for arbitration, with any necessary adjustments in subsequent payments for overpayments or underpayments arising out of the decision of the arbitrator with respect to the determination. If the employer fails to make timely payment in accordance with such final decision, the employer shall be treated as being delinquent in the making of a contribution required under the plan (within the meaning of section 1145 of this title).
Notwithstanding subsection (d) and section 1399(c) of this title, if an employer contests the plan sponsor’s determination under paragraph (1) through an arbitration proceeding pursuant to subsection (a), or through a claim brought in a court of competent jurisdiction, the employer shall not be obligated to make any withdrawal liability payments until a final decision in the arbitration proceeding, or in court, upholds the plan sponsor’s determination.