Ending the monarchy would halt these absurdities

The common thread running through most of this is the baleful influence of a monarchical system

In trying to make sense of the dramatic collapse of the trial of Paul Burrell, butler to the late Diana, Princess of Wales, let us start with the behaviour of some of the minor actors in the drama. For we shall see that otherwise sensible people behave absurdly once royalty is present.

Look, for instance, at the way the judge, Mrs Justice Rafferty, conducted the trial. She failed to observe the interests of justice. She ordered that certain evidence should be kept secret because it might affect the Princess's two sons.

She also held up the trial for three days while she engaged in discussions with the prosecution about the handling of the Queen's evidence, when all that was needed was to get it on to the public record as soon as possible. Indeed, the interests of justice demand that trials be openly conducted unless the security of the state is threatened. And, of course, nothing of this nature was at stake. Why did she give me the impression that securing a fair trial for the person who was charged, the unemployed butler, meant less to her than the peace of mind of the Royal Family? The reason was the judge's absurd deference.

Turn to another establishment character: the Queen's solicitor, Henry Boyd- Carpenter, a partner with Farrer & Co. Mr Burrell's solicitor, Andrew Shaw, sought a meeting with him to bring to his attention what he stated in a letter to the Queen, that the evidence likely to be presented in court would be embarrassing and distressing for the Royal Family. Mr Boyd-Carpenter refused to see him. Here, it seems to me, Mr Boyd-Carpenter was displaying one of the unpleasant characteristics of the typical courtier – self-importance. Had he listened to Mr Shaw, he might have concluded that a miscarriage of justice, embarrassing to the Royal Family, was in the making.

Likewise the Queen's staff, who one presumes must have read Mr Shaw's letter, even if Her Majesty herself did not. Why did they ignore the warning? Here, no mystery exists any longer. For the answer is that members of the Royal Family had been briefed specially by the police, and they believed what they had heard.

However, as we have learnt, the police story – that Mr Burrell had been selling the Princess's possessions and pocketing the proceeds – was completely untrue. In reading about the many police blunders we are at once both surprised and not surprised – astonished that, even in a high-profile case, police work could be so poor, yet reminded of so many similar fiascos.

Let us continue to be amazed. First, because this investigation was directed by the Metropolitan Police and overseen by the Commissioner himself, Sir John Stevens. These are supposedly our finest police officers. And secondly because, when the police became aware of their errors, they made no attempt to correct the misleading impressions they had created. They could have halted a possible miscarriage of justice, but they declined to do so.

I suggest that, in future, all police reports should carry the warning: "This work may have been carried out by officers who are either incompetent or who disregard evidence which fails to fit their preconceptions, or both."

It takes two, however, to bring a case to court: the Crown Prosecution Service as well as the police. The Director of Public Prosecutions, Sir Derek Calvert-Smith QC, shouldn't have needed any warning about the quality of police work; he must have seen its deficiencies many times. Thus put on guard, all that remained to do was to apply common sense to the files. Where was the hard evidence to support the case? What had Mr Burrell said to the Queen? Alas, good judgement was again conspicuously missing.

A common thread runs through most of this. It is the baleful influence of a monarchical system on public life. The judge extends unfair privileges to the Royal Family during the trial. She doesn't see them as the perfectly ordinary people they undoubtedly are. The Queen's solicitor likewise deludes himself about his own status, no doubt thinking that it would be unseemly to meet the representative of a mere butler. The police, too, often convince themselves that a particular outcome to a case is strongly desired, either by public opinion or by the establishment, and they then set out to provide whatever they imagine to be the required answer. In this case, they were blinded by the royal involvement. Then, one of the checks and balances in our ramshackle system fails to work – the CPS presses on regardless.

All of which is why I have long believed the UK should have a written constitution, entrenched rights to protect the citizen and some other method of choosing the head of state. It's no use going on tinkering, this time wondering whether the Queen's relationship to her courts needs clarifying. The whole thing is an absurdity.