How have courts interpreted the definition of reasonable doubt in a sexual assault case?

Notwithstanding the fact that the trial court gave a standard instruction before the jury deliberated, the appellate court held: "[The trial] court's tinkering with the statutory definition of reasonable doubt, no matter how well intentioned, lowered the prosecution's burden of proof below the due process requirement of proof beyond a reasonable doubt. [Citations.] Lamentably, 'the essential connection to a "beyond a reasonable doubt" factual finding cannot be made where the instructional error consists of a misdescription of the burden of proof, which vitiates all the jury's findings.' [Citation.] The error 'unquestionably qualifies as "structural error"' and compels reversal per se. [Citations.]" (People v. Johnson, supra, 119 Cal.App.4th at pp. 985-986.)