In any proceeding under N.H. Rev. Stat. § 374:33 in which the public utilities commission determines that the proposed acquisition is not lawful, proper, or in the public interest, the public utilities commission shall review the costs incurred by the target company incident to the proceeding, determine which of those costs are reasonable and prudently incurred, and shall then require that the unsuccessful acquirer reimburse such costs to the target company. The public utilities commission is further prohibited from including in rates to ratepayers any of the costs, including, without limitation, all disbursement, expert witness fees, and reasonable attorney’s fees incurred by either party in such proceeding. This section shall not apply to costs and expenses incurred prior to July 19, 1991.