On neutral ground
Attorney Miles Carter advises on the importance of being objective when acting as an expert witness
Most medical negligence cases stand or fall on the quality of the expert evidence available
Must an expert witness in a medical malpractice case put on his gloves, take up the cause, and fight for the party who instructs him or her?
Most medical negligence cases stand or fall on the quality of the expert evidence available. The primary function of a medical expert (and indeed any expert witness) is to guide the court to a correct decision on questions falling within that expert’s specialised field. The expert should be independent and objective.
The role of an expert
The question of reasonableness and negligence of a medical practitioner is one for the court itself to determine
The Supreme Court of Appeal of South Africa has said the following in regard to the role of an expert:
- The question of reasonableness and negligence of a medical practitioner is one for the court itself to determine on the basis of the various, and often conflicting, expert opinions presented. As a rule that determination will not involve considerations of credibility but rather the examination of the opinions and the analysis of their essential reasoning, preparatory to the court reaching its own conclusion on the issues raised.
- What is required of the court in the evaluation of such evidence is to determine whether and to what extent the opinions of the various experts are founded on logical reasoning.
- The court is not bound to absolve a defendant from liability for allegedly negligent medical treatment or diagnosis just because evidence of expert opinion, albeit genuinely held, is that the treatment or diagnosis in issue accorded with sound medical practice. The court must be satisfied that such opinion has a logical basis – in other words that the expert has considered comparative risks and benefits and has reached a “defensible conclusion”.
- A defendant can probably be held liable, despite the support of a body of professional opinion sanctioning the conduct in issue, if that body of opinion is not capable of withstanding logical analysis and is therefore not reasonable. However, it will very seldom be right to conclude that views genuinely held by a competent expert are unreasonable.
- The assessment of medical risks and benefits is a matter of clinical judgment which the court would not normally be able to make without expert evidence, and it would be wrong to decide a case by simple preference where there are conflicting views on either side, both capable of logical support. Only where expert opinion cannot be logically supported at all will it fail to provide “the benchmark by reference to which the defendant’s conduct falls to be assessed”.1
Expert scientific witnesses do tend to assess likelihood in terms of scientific certainty
It must be borne in mind that expert scientific witnesses do tend to assess likelihood in terms of scientific certainty. Some of the witnesses in a case before the SCA had to be diverted from doing so and were invited to express the prospects of an event’s occurrence, as far as they possibly could, in terms of more practical assistance to the forensic assessment of probability, for example, as a greater or lesser than 50% chance, and so on.2
The essential difference between the scientific and the judicial proof has been highlighted in a Scottish case, which our courts follow, in which it was said that: “One cannot entirely discount the risk that by immersing himself in every detail and by looking deeply into the minds of the experts, a judge may be seduced into a position where he applies to the expert evidence the standards which the expert himself will apply to the question whether a particular thesis has been approved or disproved – instead of assessing, as a judge must do, where the balance of probabilities lies on a review of the whole of the evidence.”3
An expert witness should provide independent assistance to the court by way of objective, unbiased opinion
Our courts have also referred with approval to another English case, in which the duties of an expert witness were said to be as follows:
- Expert evidence presented to the court should be, and should be seen to be, the independent product of the expert uninfluenced as to form or content by the exigencies of litigation.
- An expert witness should provide independent assistance to the court by way of objective, unbiased opinion in relation to matters within his expertise. An expert witness should never assume the role of an advocate.
- An expert witness should state the facts or assumptions upon which his opinion is based. He should not omit to consider material facts which would detract from its concluded opinion.
- An expert witness should make it clear when a particular question or issue falls outside his expertise.
- If an expert opinion is not properly researched because he considers that insufficient data is available, then this must be stated with an indication that the opinion is no more than a provisional one. In cases where an expert witness who has prepared a report could not assert that the report contained the truth, the whole truth and nothing but the truth without some qualification, that qualification should be stated in the report.
Not a ‘hired gun’
The Cape High Court has recently said that, in short, an expert comes to court to give the court the benefit of his or her expertise. During a case, which did not involve medical malpractice, the Judge said: “Agreed, an expert is called by a particular party, presumably because the conclusion of the expert, using his or her expertise, is in favour of the line of argument of the particular party.
An expert is not a hired gun who dispenses his or her expertise for the purposes of a particular case
"But that does not absolve the expert from providing the court with as objective and unbiased opinion, based on his or her expertise, as is possible. An expert is not a hired gun who dispenses his or her expertise for the purposes of a particular case.
"An expert does not assume the role of an advocate, nor give evidence which goes beyond the logic which is dictated by the scientific knowledge which that expert claims to possess.”4
Although the case before the Cape High Court was not a medical malpractice claim, the principles enunciated apply equally to all expert witnesses.
The Judge said that it was clear that X (the expert witness) was “hired as a person specifically to undermine Y’s evidence, before she considered the facts. Although I have to accept that she did try to place an impartial gloss on much of the evidence, her reluctance to concede, when faced with a clear obstacle, her inability to acknowledge the possibility of another expert’s view and the general contradictory nature of her evidence… has to be evaluated in terms of the mandate that she was given… What was so significant about X’s performance was the fact that it was obvious, both from her demeanour and her reluctance to answer, that she knew that this [a programme that she supported in her evidence], was an unsuitable programme.
The medical expert’s function is not to fight the case of the party who calls him
"After the most intricate of evidential egg dances, she finally, reluctantly, conceded that it may well not have been suitable. In my view, her evidence raises significant problems as to her independence, credibility and her expertise.
"Secondly, [the evidence] reveals that X was brought in as an expert, apparently with the connivance of the first respondent’s attorney, as ‘a hired gun’. Again, none of these facts were ever brought to the attention of the court until cross-examination took place.”
It is clear from all of this that the medical expert’s function is not to fight the case of the party who calls him.
Perils and pitfalls
If an expert does take up the gloves for a party, not only is his reputation potentially at risk, but he exposes himself to the risk of civil claims
If an expert does take up the gloves for a party, ignoring the principles set out above, not only is his reputation potentially at risk, but he exposes himself to the risk of civil claims and of complaints to the HPCSA.
In one matter in which MPS represented a member, an expert witness for the plaintiff conceded under cross-examination that he would only be paid if the plaintiff won.
No matter how frank his evidence was, his independence and objectivity immediately came under scrutiny. He should never have placed himself in this position.
So what are the lessons to be learned?
- When volunteering to give evidence as an expert, practitioners should take care to remain in their own area of expertise.
- Practitioners should be wary to give evidence as an expert on behalf of a patient if their relationship with the patient is of such a nature or such a duration as to render their independence and objectivity questionable.
- A practitioner must not be, or risk being seen as, a hired gun.
- In short, the expert is there to assist the court, and not to fight the cause of the party paying him, and he must provide the court with as objective an unbiased opinion, based on his expertise, as is possible.
Miles Carter is a partner at Bowman Gilfillan, Johannesburg, South Africa.
- Bolitho v City and Hackney Health Authority  AC 232 (H)
- Michael v Linksfield Park Clinic (2001) (3) SA 1188 (SCA)
- Dingley v The Chief Constable, Strathclyde Police 200 SC (HL) 77
- Schneider NO & Others v AA & Another (2010) (5) SA 203 (WCC)