What is the standard of error for instructing the jury that a box cutter is a deadly weapon?

Applying a different standard of error in this case would be particularly anomalous. If the trial court had simply instructed the jury that a box cutter was a deadly weapon as a matter of law, and given no correct instruction whatsoever, the error would clearly be subject to Chapman harmless error review. ( People v. Brooks (2017) 3 Cal.5th 1, 69, 219 Cal.Rptr.3d 331, 396 P.3d 480 [misdescription of an element of a charged offense].) But here, the court also provided the jury with a valid theory. Providing the jury with

[8 Cal.5th 12]