The Court may draw adverse inferences from a party’s failure to deploy forms of evidence or proof which he/she could reasonably have been expected to adduce. Thus, in appropriate cases “a court may be entitled to draw adverse inferences from the absence or silence of a witness who might be expected to have material evidence to give on an issue in the action”, unless a credible reason is given for the witness’s absence: Wisniewski v Central Manchester HA [1998] PIQR P324 at 340. As Lord Leggatt explained in Efobi v Royal Mail Group Ltd [2021] 1 WLR 3863 at §41, this is “a matter of ordinary rationality” and a feature of the process of a Court drawing inferences:

“So far as possible, tribunals should feel free to draw, or to decline to draw, inferences from the facts of the case before them using their common sense without the need to consult law books when doing so. Whether any positive significance should be attached to the fact that a person has not given evidence depends entirely on the context and particular circumstances. Relevant considerations will naturally include such matters as whether the witness was available to give evidence, what relevant evidence it is reasonable to expect that the witness would have been able to give, what other relevant evidence there was bearing on the point(s) on which the witness could potentially have given relevant evidence, and the significance of those points in the context of the case as a whole.”