then such finding by an arbitrator or final judgment by a court shall be deemed a finding that the plaintiff's claim against such defendant was substantially frivolous, substantially groundless, or substantially vexatious. Upon such a final judgment or finding, such excluded party shall be entitled to an award of reasonable and necessary attorneys' fees and expenses of litigation upon the filing of a motion. The court or arbitrator shall award only such reasonable and necessary attorneys' fees and expenses of litigation as the court or arbitrator determines were related to the defense of only such excluded party and not to the defense of other defendants in such action, unless otherwise authorized by law. Such attorneys' fees and expenses so awarded shall be assessed against the party asserting such claim, against such party's attorney, or against both in such manner as is just.
OCGA § 31-7-3.3