What is the standard of prejudice when a jury fails to instruct the jury on the potential effect of provocation to reduce murder to manslaughter?

voluntary manslaughter]; People v. Thomas (2013) 218 Cal.App.4th 630, 633 [applying the Chapman test to the court's failure to instruct the jury on the potential effect of provocation to reduce murder to manslaughter].)

For our purposes, it is not necessary to decide which standard of prejudice applies because any error was harmless even under the more stringent Chapman standard. (See Peau, supra, 236 Cal.App.4th at p. 830.) "Error in failing to instruct the jury on a lesser included offense is harmless when the jury necessarily decides the factual questions posed by the omitted instructions adversely to [the] defendant under other properly given instructions. [Citation.]" (People v. Lewis (2001) 25 Cal.4th 610, 646.) The failure to give a heat of passion instruction was harmless beyond a reasonable doubt because the jury necessarily rejected the possibility that the defendant acted in the heat of passion by convicting him of first degree murder. (See Peau, supra, 236 Cal.App.4th at p. 828.)