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An expert’s duty: to the court or instructing attorney?

07 July 2021

Karmen Winfred, Claims Manager at Medical Protection, looks at a case where an expert witness failed in their duty of impartiality

During the lifespan of a case or claim, it is likely that expert evidence will be required to assist in determining the reasonable standard of care of a healthcare practitioner. At Medical Protection we recognise that members might be called upon in various circumstances to offer expert evidence in cases involving alleged medical negligence.

An expert’s role in a case or claim is vital in determining whether or not a doctor is negligent. To this end, our courts have aided us in explaining the duty of an expert in medical negligence matters.

Case study: a typical hired gun

In MV v the MEC for Health, Gauteng[1] the claimant was admitted to Kalafong Hospital on 19 October 2013 at 17.20, being 38 weeks pregnant, complaining of pain of the left side of her abdomen. At 15.10 the claimant was dilated to 9cm and molding and caput was diagnosed. The doctor on duty then decided to perform a caesarean section. The claimant was discharged on 24 October 2013.

On 28 October 2013, the claimant was readmitted and underwent an evacuation, which was converted to a full laparotomy and hysterectomy, during which her uterus and one of her ovaries was removed. The results showed that the claimant had suffered from severe sepsis, which necessitated the performance of the hysterectomy that was necessary to save her life.

Dr B, an expert obstetrician and gynaecologist was appointed on behalf of the claimant, while Dr M was appointed as an expert by the state attorney on behalf of the defendants.

It was found during Dr M’s cross examination that he advocated for the defendant without proper consideration of the medical records and without having done proper research. He further expressed an opinion on the claimant’s psychological state without considering all the facts and without being qualified to do so.

The court noted that Dr M was “patently influenced by the litigation and its exigencies”. It went further to state that Dr M’s opinion was not founded on logical reasoning as alluded in his evidence in chief and cross examination. His evidence was noted to be poor, biased and unreasonably inflexible. The judge gained an impression that he was partisan in giving evidence that affected his credibility and noted that Dr M was a “typical hired gun” that was called to give evidence for the defendants when the facts speak for themselves.

In drawing its conclusion on Dr M, the court had regard for the case of Lord ArbInger v Ashton,[2] in which it was stated: “There is an undoubted bias to serve those who employ and remunerate you. It is very natural and effectual that we constantly see persons, instead of considering themselves witness, rather consider themselves paid agents of the person who employs them.”

Where the expert’s duty lies

With consideration for this natural inclination as stated in Ashton above, the court in MV reiterated the principles of an expert’s duty by stating that an expert witness is employed to assist the court in deciding issues in which the court does not have the ordinary and requisite expertise.

Experts are also duty bound to provide the court with an objective and unbiased opinion based on his or her expertise as possible. An expert is not a “hired gun” who dispenses their expertise for the purposes of a particular case. An expert does not assume the role of an advocate nor gives evidence that goes beyond the logic that is dictated by the scientific knowledge that the expert claims to possess.[3]

Notwithstanding the impartiality of an expert, the determination of the probable value and weight of an expert witness’ evidence is not always about credibility. Furthermore, judicial officers must caution against allowing the opinion of an expert witness to take the place of their own finding of fact.

Based on the conclusions drawn against Dr M, his evidence was disregarded in totality as it proved no assistance to the court. The claim was, therefore, upheld.



[1] [2020] ZAGPPHC 223

[2] (1873) LR Eq 358 at 374

[3] Schneider NO and Others v AA and Another 2010 (5) SA 203 (WCC) and 211