He was one of the best-known and most highly regarded litigation experts in the country in the field of IT.
In a written appreciation, Peter Susman QC, barrister Terry Bergin and solicitor Amina Somers said he had been instructed in more than 100 cases in which the efficiency of computer software was in question; gave evidence in most of the well-known reported cases in the field; and nearly always had his evidence accepted by the tribunal.
"The reasons were not hard to find. He had a wealth of knowledge and experience of business and accounting methods as well as of IT. He was always analytical, always intellectually rigorous, and had the gift of putting complicated technical matters in language that other professionals could readily understand," they said.
"If your case was strong, he said so, and you pursued it and won. If your case was weak, he said so, and you settled. If your case was hopeless, he said so, and you gave up. Whatever his view, he expressed it fearlessly. Whatever concession ought to be made, he would make it without hesitation. He said the same in the court as out of it, and in the same measured and reasoned tones, and he was never rattled.
"He was nearly always calm, urbane and cheerful. He only occasionally showed mild irritation by a shrug of the shoulders if he thought the opposing expert was being less than straightforward. He had used his initiative and imagination to found SRL Consultants, to provide a team of IT experts for substantial and complex litigation, and more recently CICS Conciliation Service, a pioneering scheme for resolving computer disputes.
"He was a good man to have on your team and to have as a friend. He will be sadly missed by colleagues and clients as well as by his family, to whom he was devoted."
Larner will also be missed by Computer Weekly, which regularly called on him for advice in identifying the causes of IT disputes.