In what circumstances have courts found there was insufficient evidence to support a claim by a defendant that he was involved in a robbery prior to the victim's death?

In contrast, in People v. Lewis (1990) 50 Cal.3d 262, the court stated "[t]here was no evidence that the offense, if committed by defendant, was other than robbery. The victim had been brutally murdered and some of his property was missing. He was in possession of his car when last seen alive, and it was missing when his body was discovered." (Id. at p. 277.) Moreover, "[t]here was nothing more than sheer speculation to support the scenario now advanced by defendant that the idea of taking the victim's property did not arise until after the victim was dead." (Ibid.; accord, People v. Duncan (1991) 53 Cal.3d 955, 971.)