Justice Raper agreed that the conviction should be affirmed, but rejected the majority's recognition of traumatic automatism as a defense available under a general not-guilty plea. In his view, the psychiatrist's testimony was inadmissible because Fulcher had not entered the required plea of not guilty by reason of mental illness or deficiency.
Raper read Wyoming's statutory definition of mental deficiency—which expressly includes brain damage—as controlling. Since Fulcher's own expert characterized the alleged concussion as brain injury or brain damage, Raper concluded that Fulcher's claim necessarily invoked a statutory mental-deficiency defense and had to comply with its plea and examination requirements.
The statutory procedure serves both the defendant and the public, Raper explained. A court-ordered, impartial psychiatric examination can determine whether an asserted injury is temporary, permanent, recurrent, feigned, or part of a broader condition requiring treatment or supervision. Permitting a defendant to relabel brain damage as "traumatic automatism" would evade that safeguard.
Raper also disputed the majority's premise that a mental-illness-or-deficiency verdict automatically produces inappropriate institutionalization. Wyoming law permits discharge, conditional release with supervision, or commitment depending on the person's condition and danger to self or others. He would therefore leave any concussion-based claim within the statutory mental-responsibility framework rather than create a separate route to outright acquittal.