The practice of literary criticism can be hazardous to the reputation of a critic. This is especially the case for a critic who identifies ‘errors’ in the work under consideration that are not errors at all, or who makes silly blunders of his or her own in the course of a nit-picking review.

Sadly for him, Lewis Jones fell into both of these traps in last week’s lead review in the Spectator. The book he was writing about was one I had just read: Marcus Scriven’s Splendour & Squalor (Atlantic Books, £25). It deals with the rackety lives of four British aristocrats of the 20th century: the 7th Duke of Leinster – whose son, formerly the Marquess of Kildare, was chairman of Kidlington-based CSE Aviation – the 12th Duke of Manchester, the 6th Marquess of Bristol and his son, the 7th Marquess (pictured) whom I knew, before he succeeded to the peerage, when he was John Jermyn. I liked the book very much, not least for the quality of Scriven’s writing. Jones was not so keen.

His lack of enthusiasm was not apparent, however, until late in the review. Eight fat paragraphs at the beginning presented a summary of many of the startling facts about the “pair of Bristols” (Jones could not resist the pun) that, for me, had made the book such compelling reading.

The seventh dealt with the son’s massive spending (an estimated £20m) on drugs, his preference for boys over girls (“Rupert Everett makes a cameo appearance, sulking in leathers and a diamond choker”) and his unhappy marriage: “Shortly before dawn on their wedding night his bride found him in the East Wing at Ickworth [his ancestral home in Suffolk, by then the property of the National Trust], freebasing cocaine with some friends. She told him she wanted to go to bed, and he told her to f*** off.”

Paragraph eight concerned, in part, his escapades as a pilot: “He was especially fond of helicopters, and after a few bottles at dinner would hover over the quarters of the estate’s National Trust employee and scream abuse at him through a megaphone. Flying home from London once he mistook his home for a sugar beet factory in Bury St Edmunds and landed on its roof. As Terry-Thomas would say, he was an absolute shower.”

An arch-pedant might insist on ‘would have said’, since Terry-Thomas is long dead. But would the gap-toothed actor have said it of an individual? The Concise Oxford Dictionary defines shower as “a group or crowd of people (usually derogatory), a pitiful collection or rabble”.

The sentence that immediately precedes it in Jones’s review contains another error: Lord Bristol did not mistake his home for a sugar beet factory; rather he mistook a sugar beet factory for Ickworth, for it was on the factory roof that he landed.

These slips would not bother me had Jones not gone on to be so censorious over alleged mistakes in Scriven’s writing. Taking his cue from the generous tribute Scriven offers, in his acknowledgments, to the late Hugh Massingberd (“whose enthusiasm was and remains a source of inspiration”), Jones says this “formidable scholar” (well, a bright bloke, certainly) would have discovered a great deal to find fault with had he been given the book to review.

One example: Scriven twice mentions that the 7th Duke of Leinster kept snakes at Eton but spells the receptacle for their storage first as an ‘ottoman’ and second as an ‘Ottoman’. Venial, or what?

Next he quotes a sentence from the book concerning the legal consequences of the duke’s 15-hour drive from London to Aberdeen to win himself a £3,000 bet: “Summonsed for failing to produce his licence, he notched up two speeding fines the following week (when his licence was ‘eventually tracked down it showed convictions dating back to 1914’).”

Jones comments witheringly: “Massingberd would have deplored that illiterate ‘summonsed’, that knackered parenthesis and that unattributed quotation; and he would have pointed out that driving licences did not become compulsory until 1935.”

I think it presumptuous of Jones to tell us what Massingberd would have done. Stupid, too, unless he wants us to believe that his hero was in the habit of talking through his hat.

First, ‘summonsed’ is not illiterate but entirely correct, as study of the relevant entry in any dictionary will reveal.

Second, while the parenthesis may be knackered (though I don’t think so, in part because I don’t know what this means) there can be no doubt that it is permissible.

Third, the quotation, while unattributed, was obviously supplied by an official of the court that dealt with the speeding charges. And which court was this? The one to which he was summonsed at the behest of the “local constabulary” whose interest in the duke’s reckless exploit is mentioned in the sentence preceding the one quoted.

Finally – and surely Jones’s silliest error – driving licences were not made compulsory in 1935, as he says, but more than 30 years earlier, in 1904. This was when they were introduced and drivers needed one from the very beginning. What happened in 1935 was that drivers had, for the first time, to pass a test to obtain one.

Members of the jury, speaking in defence of the much-maligned Mr Scriven, I rest my case.