On appeal, the Eighth Circuit Court of Appeals reversed Gonzalez-Lopez's conviction, ruling that the district court erred both in ruling that Low violated the rules of professional conduct and in refusing to allow Low to represent Gonzalez-Lopez. It further ruled that the error in denying Gonzalez-Lopez his right to choice of counsel (Low) was "structural" in nature—i.e., reversible without harmless error analysis. The prosecution then petitioned for certiorari from the United States Supreme Court. It did not dispute that the district court erred and improperly denied Gonzalez-Lopez his choice of counsel, but argued that such error should be subject to harmless error analysis, and that Gonzalez-Lopez was not prejudiced by the error.