What is the test for a sua sponte instruction on provocation and second degree murder?

As defendant observes, a sua sponte instruction on provocation and second degree murder must be given "where the evidence of provocation would justify a jury determination that the accused had formed the intent to [6 Cal.4th 43] kill as a direct response to the provocation and had acted immediately" to carry it out. (People v. Wickersham (1982) 32 Cal.3d 307, 329, 185 Cal.Rptr. 436, 650 P.2d 311.) Wickersham noted that "the fact that heated words were exchanged or a physical struggle took place between the victim and the accused before the fatality may be sufficient to raise a reasonable doubt" as to premeditation. (Ibid.) Defendant argues that because the trial court apparently found sufficient evidence to justify giving a provocation/manslaughter instruction, then a fortiori there must have been enough evidence to instruct on second degree murder.