What is the test for overturning a conviction for sexual assault against a police officer?

Evidence Code section 352; (6) defendant's conviction on count 3 must be reversed because he acted alone in the commission of the offense; (7) defendant seeks appellate review of police officer personnel records pursuant to Pitchess v. Superior Court (1974) 11 Cal.3d 531 (Pitchess) to determine whether any relevant documents were erroneously withheld from disclosure by the trial court; and (8) the prejudice from these cumulative errors necessitates reversal of his convictions.