Damages assessed for change of grade under the provisions of this subdivision shall be paid by the town in which the change of grade is made; provided, however, that no highway shall be deemed to have been repaired by the authority of the town unless the town participated directly in the repair of the said highway other than financially, or unless the town in some manner exercised control over the manner in which the highway construction or maintenance was performed, or unless town employees, as defined in N.H. Rev. Stat. § 235:38, were employed in the said construction or maintenance work involved in the repair or construction of said highway.