State ex rel. Department of Workforce Services v. Williams, 409 P.3d 1219

On June 21, 2014, Richard Williams, a well operator working alone at a gas processing site, fell backward on an elevated platform while emptying condensate and struck the back of his head on concrete. He reported a flash fire, used a fire extinguisher, called 911, was life-flighted, and was diagnosed with a closed head injury, occipital hematoma, post-concussive syndrome, and later PTSD and neurocognitive deficits.
OSHA and the site owner concluded a flash fire could not have occurred; the Division relied on that finding and denied workers’ compensation benefits, concluding the injury did not arise out of employment.
OAH affirmed the denial, finding Williams not credible and rejecting medical evidence as based on an inaccurate history (i.e., a nonexistent fire).
Williams petitioned for district court review; the district court reversed, holding that even if no fire occurred, the undisputed evidence established a work-related fall causing the head injury.
The Wyoming Supreme Court reviewed de novo (administrative appeal) to decide whether OAH’s rejection of Williams’ claim was contrary to the overwhelming weight of the evidence.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether OAH’s denial of benefits was contrary to overwhelming evidence	Williams: medical records and testing show a fall at work caused a traumatic brain injury; presence on premises plus unrebutted medical evidence raises a presumption of work causation	Division: presence on premises alone is insufficient; OAH properly discredited Williams and relied on OSHA finding that no flash fire occurred, undermining his story	Court: Williams raised the premises presumption and produced unrebutted medical and task-specific evidence; Division rebutted only the fire, not that a work-related fall or head injury occurred — reversal of OAH affirmed

Archuleta v. Carbon Cty. Sch. Dist. No. 1, 787 P.2d 91 (Wyo. 1990) (adopts premises rule: on-premises injury raises rebuttable presumption of work causation)
Finley v. State ex rel. Wyo. Workers' Safety & Comp. Div., 132 P.3d 185 (Wyo. 2006) (presence on premises insufficient alone to conclusively establish causal nexus)
Price v. State ex rel. Dep’t of Workforce Servs., Workers’ Comp. Div., 388 P.3d 786 (Wyo. 2017) (standard for reviewing administrative rejection of claimant evidence; whether conclusion is contrary to overwhelming weight of evidence)
Gomez v. State, 231 P.3d 902 (Wyo. 2010) (describes burden to prove injury arose out of and in course of employment)
Perry v. State ex rel. Wyoming Workers’ Safety & Comp. Div., 134 P.3d 1242 (Wyo. 2006) (focuses inquiry on whether injury occurred while engaged in a task that is part of employment)