HT-2022-000090 - [2025] EWHC 723 (TCC)

Mr Alyah’s evidence, drawn from his unchallenged evidence about the consequences of the types of defects identified in the 10 samples, together with his view about the prevalence of those defects, was that there would be progressive degradation and an increased risk of premature failure as a direct result of the issues he identified in his report. It was put to him, and he accepted, that he had not carried out a quantitative evaluation, via a mathematical probability calculation, of the risk or other calculation in the life span of the cables on account of the defects. However, there is no evidence, for the reasons explained, from an expert identifying how just such any quantitative could be undertaken, given that it would, by definition, depend on assumptions as to precise numbers and types of defects. It would on any view therefore be highly subjective and subject no doubt to criticism of the assumptions adopted. I do not therefore consider that the absence of a quantitative assessment in the circumstances of this case detracts in any way from Mr Alyah’s conclusion based upon, as he put it in evidence, ‘studies after studies after studies that have been documented by a lot of organisations that these types of deviations will lead to accelerated degradation of the insulation and eventually lead to a premature failure.’

I conclude that it was objectively reasonable to assume, when determining the appropriate remedial scheme, that the defects were widespread and that they would lead to progressive degradation of the integrity of the circuits. As such, it was reasonable to adopt a scheme which addressed the avoidance of future, premature failure of the circuits.