Does the Attorney General have a valid argument that if a trial court erred, if the error was harmless, is that error harmless?

The Attorney General contends that if the trial court erred, the error was harmless. Defendant argues we should apply the standard of Chapman v. California (1967) 386 U.S. 18, 24 [harmless beyond a reasonable doubt], and determine that the error was not harmless. Defendant argues that the error was not harmless even under the standard of People v. Watson, supra, 46 Cal.2d at p. 837 [more favorable outcome for defendant reasonably probable absent error]. We conclude that the error was not harmless under either standard.