Does a trial court have an obligation to sift through the evidence to identify an issue that conceivably could have been but was not raised by the parties?

restraint. However, a trial court is "under no obligation to sift through the evidence to identify an issue that conceivably could have been, but was not, raised by the parties, and to instruct the jury sua sponte, on that issue. . . . '[When a theory is] so far under the surface of the facts and theories apparently involved as to remain hidden from even the defendant until the case reached this court on appeal[,] . . . [t]he trial court need not . . . have recognized it and instructed the jury in accordance with it. Omniscience is not required of our trial courts.' " (People v. Montoya, supra, 7 Cal.4th at p. 1050.) Indeed, the record implicitly suggests that the court and the parties agreed there was no evidence of excessive force, as suggested by the trial court's deferral of the issue until the receipt of all evidence, and the subsequent failure to give the instruction with no further discussion on the record.