In what circumstances will a court overturn a conviction of first degree murder based on a hallucination?

In People v. Padilla (2002) 103 Cal.App.4th 675 (Padilla), the defendant was charged with the murder of his cellmate. (Id. at p. 677.) During the guilt phase, the trial court rejected the defendant's attempt to admit the testimony of two psychologists that the killing was retaliatory after the defendant hallucinated that his cellmate killed the defendant's father and brothers. (Ibid.) One of the psychologists would have testified that the defendant hallucinated and the other would have testified about the concept of a hallucination as provocation. (Id. at p. 678.) The appellate court held that a subjective test applies to determine "whether provocation or heat of passion can negate deliberation and premeditation so as to reduce first degree murder to second degree murder...." (Ibid.) Finding the jury could have concluded the defendant's hallucination provoked a heat of passion and reduced the murder from first degree to second degree, the court vacated the judgment of conviction on first degree murder. (Id. at pp. 678-679.)