The case concerned wedding pictures of the two Hollywood film stars taken in New York for a Spanish publication, Hello! The trial was held in London for much the same reason as are the Olympics. The British public sector can be guaranteed to invest the most trivial event with pomp, dignity and stupefying expense. There is also a good chance of getting away with murder if the money is right. Even so, why the law lords felt obliged to act as judicial extras in a "spoiler" row between two magazine picture desks is a mystery. The only plausible explanation is that British judges are suckers for a glamour trial and will sell their services anywhere to get their hands on one.

The actual judgment on Wednesday was barking mad. The Douglases had sold "exclusive rights" to take pictures of their 2000 wedding for £1m to OK!. The event was to be an intimate affair confined to 350 of the couple's closest celebrities and costing a mere £1.2m. To stress this intimacy it was held not in that paparazzi-infested cauldron of fame, Swansea (Zeta-Jones's home town), but in a secret hideaway that bore a marked resemblance to Manhattan's Plaza hotel. In other words, this was not a private wedding but a showbusiness one, its publicity value so calibrated as to maximise revenue.

Crucial to the deal was a promise by the Douglases to OK! that no other cameras would be allowed inside the Plaza. Rivals naturally rose to the challenge. A photographer for Hello! magazine gained entry by posing as "a guest or waiter", callings apparently indistinguishable among celebrities. He escaped with his scoop and his pictures were published on the same day as those in OK!, depicting the usual banal images of faces, clothes, champagne, cake and glamour. It was a classic spoiler, of the sort perpetrated by Fleet Street every day of the week.

Douglas, hero of Basic Instinct and Fatal Attraction, contrived to find the Hello! pictures "seedy and voyeuristic". Zeta-Jones swore on oath that she was "devastated, shocked and appalled" by them. Despite having stripped to the waist to defend her honour in the Mask of Zorro, she regarded herself as "violated" by a shot of her being fed wedding cake with a spoon by Douglas. (The master of the rolls should have called a halt at his point: etiquette surely demands a fork.)

A normal person would have told the Douglases to dry their tears and get a life. They got their money. OK! magazine could not have possibly suffered financial loss from Hello!'s leak. Besides, as one early judge pointed out, the essence of the marriage ceremony is explicitly public, to avert bigamy (a sensible precaution in Hollywood circles). "If any of ye know cause, or just impediment, why these two persons should not be joined ... ye are to declare it." Perhaps the Book of Common Prayer should be redrafted: "Dearly beloved, we are gathered here in the sight of God and only those to whom exclusive rights have heretofore been assigned for the said million pounds."

The Douglas case was neither thrown out nor sent to some county court, as might have befitted its merits. It "opened in the West End" at the high court, which found for the Douglases in a satisfying blaze of publicity. OK! was awarded £1m in damages from Hello!. Two years later, the court of appeal reversed this judgment and now the law lords have, by a majority, reversed the reversal, concluding that Hello! was indeed liable for breaking a contract between the Douglases and OK!. An awestruck Lord Hoffman emphasised that "the point of which one should never lose sight was that OK! had paid £1m for the benefit of the obligation of confidence imposed on all those present at the wedding ... There was no reason why they were not entitled to enforce it."

As for the terrible suffering imposed by all this costly delay on the Douglases, the law courts allowed them an ex gratia payment of £14,600 for their "distress and inconvenience". Why £14,600 and not £140,600 or £1,460,000 was not explained. I suppose lawyers have never been good at noughts. But it is rumoured they did plague both houses by splitting the costs between both sides.

Clearly Hoffman is right in remarking that contracts should be enforced. But enforced by whom on whom? The Douglases would have had justice on their side in ejecting the errant photographer once they failed to spot him. But beyond that, it was surely just another celebrity wedding badly policed. The Douglases knew it and blew it.

Indeed if there was any suing to be done, OK! must surely have had a case against the Douglases for failing adequately to protect their contract. The Douglases could then have sued the Plaza hotel or their party planners for rotten security. The Plaza hotel could perhaps have sued the photographer or even Hello! for trespass. The trouble is that these suits would have been in America and would have been treated with ridicule. The only country where judges might take the farrago with sufficiently extravagant seriousness is Britain.

While courts are overcrowded, jails are jammed with prisoners waiting on remand and lawyers are professing overwork and underpay, these theatricals are enacted at Westminster. Why? Does the master of the rolls really feel that Britain should become a sort of international court for the relief of distressed celebrities? As he pondered the dusty attics and dank basements of the Inns of Court, was he struck by a vision of Chancery Lane as the Silicon Valley of fatuous litigation? (In February an equally absurd palaver went to the House of Lords over whether a lay rector should repair a particular church roof.)

As it is the courts have made fools of themselves. The Douglas case had nothing to do with the right to privacy, notoriously indefinable as it is. Nobody can stage a wedding, sell the publicity rights for £1m and then claim that they were trying to remain private. Managed publicity is not privacy. As for the "obligation of confidence" on newspapers not to scoop rivals who have paid for so-called exclusives, this is censorship born of madness. Newspapers must guard their exclusives as best they can, not call on law lords to act as their bouncers and heavies. Either way, this is a blatant case of one law for the rich and one for the poor.

The law lords are still hoping to find a new home across Parliament Square from Westminster commensurate with their newly glamorous status. They should go the whole hog and move up the road to the Ritz, where they clearly belong.

simon.jenkins@theguardian.com