A case that may inflict serious damage on the monarch and monarchy

Imagine if the Prime Minister had allowed an innocent man to go on trial while in possession of a critical piece of evidence that resulted in his acquittal. Suppose that the only plausible explanations for his conduct were either a breathtaking naivety bordering on the negligent or a deliberate attempt to manipulate justice bordering on the criminal. He would not survive in office for more than a few days.

It is fair, therefore, to ask the most sceptical questions of the Queen's account of why she brought the trial of Paul Burrell, butler to Diana, Princess of Wales, to an end.

It seems curious, to put it no higher, that the Queen did not appreciate the relevance of a conversation she allegedly had with Mr Burrell in the weeks after Diana's death until so far into the court proceedings.

It was apparent, even to casual observers, that one of the central issues was that of permission. Mr Burrell was accused of taking a lot of deeply personal property belonging to Diana without permission and for his own financial advantage. When the prosecution failed to present any evidence that he had sold or intended to sell any of the items, the question of permission became the only one.

But the outline of the case has been widely reported since Mr Burrell's arrest in August 2001. Given the importance of the case to the standing of the Royal Family – and the fact that he had been one of her personal employees for 10 years – the Queen must have taken more than a passing interest. To have failed to recognise the importance of her conversation with Mr Burrell in those circumstances is startling for someone with such a reputation for sound judgement. After all, until now she has been almost the only member of her family to float above scandal and folly.

One of the more plausible conspiracy theories is that the Queen allowed the case to go ahead because she did not mind if it harmed Diana's reputation. Yet it always risked opening old wounds – not just personally for Diana's sons but also politically for the monarchy, which handled the public response to the Princess's death badly.

Indeed, it was reported both that the Prince of Wales did not want the case to go ahead and that he was persuaded that it should only by the police wrongly accusing Mr Burrell of making money from his former wife's possessions. Not that the Prince should have had a decisive influence over the decision as to whether to proceed with the case – that was supposed to lie with the independent Director of Public Prosecutions (DPP). But now it turns out that the Royal Family had the power to halt the case all along.

Nor does concern about the case end there. No other family would be granted public-interest immunity certificates to conceal its discussions with the court from public view.

Whatever mistakes the police and the DPP may have made in preparing a transparently flawed case, its real significance lies in the Queen's apparent assumption that she should be treated differently by her own courts.

At best her defence is that she made an embarrassing mistake, an inadvertent act of omission. But if she had been anyone else, the judge in the case might have summoned the absent-minded witness and upbraided her for wasting everyone's time, putting Mr Burrell through what he described yesterday as a "terrible ordeal" and spending £1.5m of public money on a case that should never have been brought. At worst, she might have faced prosecution for obstruction of justice.

This case could do more damage to the monarchy than any amount of adultery or tawdry tape-recordings, not least because it reflects so poorly on the character of the monarch herself.