Idaho Code § 44-704

No officer or member of any association or organization, and no association or organization participating or interested in a labor dispute (as these terms are herein defined) shall be held responsible or liable in any civil action at law or suit in equity, or in any criminal prosecution, for the unlawful acts of individual officers, members, or agents, except upon proof by the weight of evidence and without the aid of any presumptions of law or fact, both of (a) the doing of such acts by persons who are officers, members or agents of any such association or organization, and (b) actual participation in, or actual authorization of, such acts, or ratification of such acts after actual knowledge thereof by such association or organization.