Does the new instruction in a felony-murder case require a jury to convict on a theory that was not introduced until after all the evidence had been received and the new instructions settled?

The court went on to hold the error was so fundamental that it could not be subjected to the harmless error standard set forth in Chapman v. California (1967), 386 U.S. 18, 87 S.Ct. 824, 17 L.Ed.2d 705. Because the felony-murder theory was not introduced until after all the evidence was received and the instructions settled the new instruction "permitt [224 Cal.App.3d 8] the jury to convict on a theory that was neither subject [ed] to adversarial testing, nor defined in advance of the proceeding." (909 F.2d at p. 1237.) The court concluded that because this error "goes to the heart of our adversarial process" it necessarily denies a defendant the fundamental right to a fair trial.