"A poor quality expert can cause serious damage...."

  • Published: February 26, 2021
  • Author: Sarah Sellars, Consultant, Inspire MediLaw

Inspire MediLaw were honoured to have Mr David Sellu address our Annual Expert Witness Conference in Oxford, which was also livestreamed.  He spoke about his case, detailing the events leading up to his conviction and imprisonment for gross negligence manslaughter, and his successful appeal in 2016.  He noted that he was comprehensively cleared of all allegations by the Medical Practitioners Tribunal Service (MPTS) in 2018, leaving him free to return to practice once again.

This experienced, well respected surgeon should have been able to trust that the legal processes to which he was subjected were fair and faultless.  The family of the patient who died were entitled to expect full and proper investigations into the death of their loved one would take place.

Mr Sellu shares his experience to encourage medical experts to understand why their role is so important.  He explains that their testimony has serious implications.  The role of the expert should be taken seriously, and medical professionals should undergo medicolegal training before first accepting instructions to provide an expert opinion.  For this reason, he was involved in developing the The Surgeon as an Expert Witnessguidance published by the Royal College of Surgeons (England) in 2019.

The expert witness plays a key role in legal proceedings, be it coronial, criminal or civil.  Experts should know and understand the different processes of these courts, and the possible outcomes of a case.  For example, while a Coroner will carry out an investigation into a death; the Civil Court will hear a claim for compensation; and Criminal proceedings could result in a conviction and, potentially, a prison sentence for the defendant.  In each Court, different legal tests are applied and the medicolegal expert should be clear on what is expected of them in this regard.

Mr Sellu warns that cases such as his make the medical profession nervous.  People become frightened by what might happen, and begin to practise defensively.  He mentioned the number of doctors who take their own lives due to professional pressures, and highlighted the huge emotional burden on a doctor who feels they have let their patient down.  

Paul Sankey, Partner and experienced solicitor in medical negligence at Enable Law, comments:

David Sellu's story should bring home to experts the importance of their role in court proceedings. 


The courts rely on them for guidance and will only be able to do justice if experts fulfil their duties. In civil cases this is a matter of ensuring the right people - those who have suffered harm from negligent care - are able to receive damages and others do not. In criminal cases, someone's liberty and livelihood may be at stake. 


David Sellu lost both and it was not until after he had served a prison sentence that his conviction was quashed. It was quashed because the judge misdirected the jury but also because the experts gave inadequate evidence, evidence which was criticised by the Court of Appeal. 


How might medical professionals as expert witnesses contribute to the proper function of our justice system?

Anyone can hold themselves out as an expert witness, regardless of their experience.  Mr Sellu advocates a programme of training, accreditation and regulation for medicolegal experts, to ensure that individuals not only grasp the importance of their duty to the Court, but understand how to carry it out.  

The role of the expert is to set out the realistic, reasonable boundaries of what should have happened and what would be expected of the medical professional in the case.   Expert witnesses should only comment on areas within their expertise, and should ensure that they express their opinion in plain English.  

At Inspire MediLaw’s Expert Witness Training we emphasise this in relation to both giving evidence in Court, and in report writing.  Mr Sellu told delegates that when his conviction was overturned, there was criticism of the experts and their testimony in his initial trial.  The experts used terms that were too complex for a lay jury, and probably also for the Judge, explained their views badly, and commented on issues that were outside their area of expertise.  

Expert witnesses are critical to delivering justice and it is right that they should be well trained, and supported to carry out their duty to the Court to the highest standard.

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