Expert v Witness Evidence

There is a tendency in litigation disputes and particularly personal injury to assume that expert evidence is required in all cases or that it is the most important factor of a case. In terms of identifying harm caused or quantification of needs, expert evidence is very helpful. In terms of what happened in a case sometimes witness evidence is much more pertinent.

Therefore, inappropriate surgical technique is hardly something on which the patient can usefully comment, whilst an expert can review operation notes and come to a view. However, a GP not taking into account the symptoms the patient mentioned is a matter on which the claimant or patient can provide evidence.

Take the recent case of Taylor and another v Raspin (2022) EWCA CIV 1613.

This was a road traffic accident case in which there was expert evidence as to speed and witness evidence as to events. In essence a motorcyclist was injured whilst driving on a main road and the defendant driver pulled out. There appears to have been some issue as to the speed of the motorcyclist and for that reason expert evidence was sought. However, this was a collision that was witnessed by others and their evidence was consistent. As the motorcyclist came into view the defendant’s car continued to pull out into a major road. That car could have stopped in time for the collision to be avoided but did not. The speed at which the motorcyclist was going was relevant but not the fundamental cause of the accident. Put simply the defendant pulled out on a minor road and continued to pull out even when the motorcyclist was in view, and she could have stopped.

The case went to appeal, and the issue was the expert v the witness evidence. The Court of Appeal considered that the expert evidence in this case was pertinent, but the fundamental facts of the case were established based on the witnesses who saw the accident and provided a consistent account of what had happened.

Witness evidence can prove as useful in clinical negligence cases.

An example of this would be LD v Rotherham NHS Foundation Trust an older case but no less relevant for that. The claimant sustained a fourth-degree tear in the course of giving birth. This is a substantial tear involving the anal sphincter causing ongoing, significant, and embarrassing problems. This can occur non negligently but in this case the claimant’s assertion was that the registrar stumbled or slipped whilst undertaking a forceps delivery. The defendant argued that that was not the case and relied on expert evidence about the frequency with which fourth degree tears occur generally.

However, the witness evidence of the claimant and her mother was absolutely clear. It was the evidence of the mother and the claimant that established the facts of the case and the court found for the claimant.

The recent case in the Court of Appeal, makes clear and reemphasises the point that expert evidence has a place, but it does not in every case supplant witness evidence which may be highly pertinent and vital.

Ultimately each case should be taken on its merits and the circumstances of cases vary. In a lot of personal injury cases witness evidence is vital. In some clinical negligence cases, witness evidence cannot always address certain issues. There are however many clinical negligence cases where that evidence is pertinent and more important to the success of a case than the opinion of an expert however eminent.

Experts cannot win a case on their own. Taylor is a timely reminder of that.