§ 19. Exclusiveness of remedy. The benefits provided by this chapter shall be the exclusive remedy of a volunteer firefighter, or his or her spouse, parents, dependents, next of kin, executor or administrator, or anyone otherwise entitled to recover damages, at common law or otherwise, for or on account of an injury to a volunteer firefighter in line of duty or death resulting from an injury to a volunteer firefighter in line of duty, as against (1) the political subdivision liable for the payment of such benefits, (2) the political subdivision regularly served by the fire company of which the volunteer firefighter is a member, whether or not pursuant to a contract for fire protection, even though any such political subdivision is not liable for the payment of such benefits in the circumstances, and (3) any person or agency acting under governmental or statutory authority in furtherance of the duties or activities in relation to which any such injury resulted; provided, however, that the benefits provided by this chapter shall not be the exclusive remedy as against persons who, in the furtherance of the same duties or activities, are not similarly barred from recourse against the volunteer firefighter, or his or her executor or administrator.