How have courts treated the issue of mistake of fact in a mental health case?

Defendant suggests that "at some critical moment in the episode [defendant] might have believed that the policeman was a public enemy of some kind, whom he would resist and vanquish." Such a suggestion is pure speculation, however, since the issue of mistake of fact based on a hallucinatory episode was not presented by the evidence produced in court and was not relied on by the defense. Indeed, a claim of mistake of fact would have been inconsistent with defendant's theory of defense and, therefore, the court was not required to instruct thereon on its own motion. (People v. Wickersham (1982) 32 Cal.3d 307, 323, 185 Cal.Rptr. 436, 650 P.2d 311.)