"It is important for those presiding over trials and appeals at the Crown Court to remember that, notwithstanding the case management powers given to them by the Criminal Procedure Rules, our system remains adversarial and is not inquisitorial. Where a judge insists on a person answering a question where the parties, and in particular the prosecution, which has the responsibility for the conduct of the case against a defendant, do not consider the issue relevant, it does give the impression that the judge has descended into the fray in an inappropriate way."