In Smith v. Throckmartin, 893 P.2d 712 (Wyo. 1995), the Court emphasized that the co-employee's actions must be willful and not merely inadvertent in nature. In that case, Mr. Throckmartin was Mr. Smith's supervisor, and, on the day of the accident, they were working together loading sand into a truck. Mr. Throckmartin operated a backhoe while Mr. Smith tamped and broke up clumps of sand in the truck bed with a metal bar. By Mr. Smith's own admission, Mr. Throckmartin hit the metal bar with the backhoe bucket by mistake causing Mr. Smith to fall from the truck bed and incur serious head and spinal injuries. The Court required the plaintiff to provide evidence the co-employee acted with a state of mind approaching intent to do harm or committed an act of an unreasonable character in disregard of known or obvious risks so great as to make it highly probable that harm would follow. 893 P.2d at 714.