George v. Bowler, 2015 MT 209, 380 Mont. 155, 354 P.3d 585 For purposes of applying the co-employee immunity rule, the simple fact that two persons have the same employer would not necessarily invoke the rule. The proper test for determining when a co-worker is an “employee” for purposes of applying the co-employee immunity rule in § 39-71-412, MCA, is whether the co-employee was acting in the course and scope of his employment at the time the negligent acts occurred.

George v. Bowler, 2015 MT 209, 380 Mont. 155, 354 P.3d 585 Separate legal entities are not considered “third parties” as that term is used in § 39-71-412, MCA, and Article II, § 16 of the Montana Constitution, when they are acting within the course and scope of their employment as co-employees of the claimant at the time the alleged negligence occurred.