second of our two-part series, we look at the medico-legal implications of being an expert witness
including key tips and traps, protecting your reputation and landmark cases.
While being an expert
witness is a professional privilege, it can be a daunting prospect for some
doctors and comes with some unique pitfalls. However, our preparation guide will
smooth the process.
Be prepared and
form your opinion
Thorough preparation is a key part of being a
credible and confident expert witness. These initial steps will help you get
- Find out the date your report is due.
- Read the relevant Expert Witness Code of Conduct.
- Read all the documents and the questions and identify
the main issues.
- You may be asked to
assume certain facts and events. Distinguish
between background history and assumptions of fact. Ensure
that you get the facts and the assumptions correct, and in the right order.
- Do your research before you put pen to paper.
- Work out how you are going to explain your opinion
and the reasons for your opinion.
- Know exactly where you obtained the information in
the documents for your report as you will need to refer to these later.
- Challenge your opinion and conclusions – is your
opinion consistent with the evidence base?
Develop clear reasoning
The reasons for any conclusions you reach and
opinions you make must be clear. It’s important to link the facts and any
assumptions to your opinion, and to ensure there is a logical flow between them.
Do not hypothesise as to what may or may not have happened in a case. If there
are any gaps in the sequence of events, check that you haven’t filled in any
factual gaps with your own facts.
If you have any concerns about your opinion, for
example, based on contradictory assumptions, address these before you write
your report. It’s a good idea to call the lawyer who engaged you in the case to
clarify your concerns and obtain more information.
If something is unclear, you may decide you need to
give more than one opinion. For example, ‘I am unable to conclude from the
documents and the assumptions provided that Dr Y warned the patient of… If he
did, then my opinion is… If he didn’t, then my opinion is…’
Be clear about the limits of your knowledge, and
don’t give an opinion outside your area of expertise.
evidence: decision traps
When forming your
opinion as an expert witness, there are a number of common traps that should be
Contradicting what’s in your report
Firstly, if the matter
goes to court, ensure that you read all the documents again,
particularly all the references you have quoted. There is nothing more
embarrassing than finding that counsel (or their expert) have read something
you quoted that contradicts your own argument.
Expert witnesses should be aware of the influence
of ‘outcome bias’, which is a tendency to judge a decision on the basis of its outcome
rather than on what factors led to the decision. Outcome bias can be avoided by
focusing on what was reasonable at the time the event happened. The court is
interested in what was competent and reasonable practice, and not was best
levels of evidence
When you are assessing a doctor’s standard of care,
it’s important to keep in mind that all guidelines are based on different
levels of evidence and to recognise the difference between a directive, a
policy, a standard, a guideline, and a position statement.
It’s important to recognise that just because a
guideline exists doesn’t mean that there is no other way to do things.
As the saying goes – hindsight is a wonderful
thing. Ensure that your view isn’t coloured by the phenomenon known as ‘hindsight
bias’. This is defined as predicting the probability of an adverse event
retrospectively. Guard against this by putting yourself in the shoes of the
doctor you are judging and look forwards, not backwards.
for the client
As an expert witness it’s easy to fall into the
trap of being an advocate for the client of the lawyer who engaged you. For
example, ‘It’s easy to imagine that Dr X would have insufficient time to assess
Mrs X’s history, discuss the ultrasound and also examine her.’ This comment
indicates that you are guessing what was in the mind of Dr X, and could be
interpreted as advocacy. You may think that a few comments can’t hurt, but as
an expert witness, your key role is to provide an impartial opinion to assist
the court make an informed and fair decision. Courts do not take kindly to
experts giving evidence which displays advocacy.
decision removes expert witness immunity
If you fail to take reasonable care in providing an
expert opinion, you will generally not be liable for civil or criminal
However, a landmark decision of the Supreme Court of the United
Kingdom has removed the protection for expert witnesses against suits by people
they had instructed to provide evidence on their behalf.
It’s important to be aware of your responsibilities
and mindful that an expert witness can face disciplinary action for evidence
given in court which is seriously flawed.
In a case in the United
Kingdom, a paediatrician gave evidence that the sudden infant deaths of two
babies in the same family could not be explained by natural causes. The paediatrician
used statistical research to support his opinion that the likelihood of two
deaths occurring from natural causes was extremely low. It was later proved
that the paediatrician had made a significant error in applying the statistics.
Subsequently, the mother of the children who had been convicted of killing both
children had the conviction overturned.
The paediatrician faced action by the General
Medical Council to deregister him. Although he escaped deregistration, the English
Court of Appeal found that expert witness immunity does not protect experts
from disciplinary action for serious substandard care in giving expert
Although rare, criminal proceedings can also result
if you act as an expert witness and deliberately lie in court or give an opinion
you do not honestly hold.
Keep the information in mind above to ensure that your
opinion is unbiased and carefully considered based on sound evidence.
The Whole Truth Handbook:
responsibilities when providing evidence can assist
doctors in giving evidence in court. Complete the course material and receive a certificate of completion and CPD points.
Download the AMA’s Ethical Guidelines for
Doctors acting as Medical Witnesses 2011. Revised 2016.
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