EXPERT WITNESSES: RARELY TOTALLY IMPARTIAL BUT SOME ARE LESS PARTIAL THAN OTHERS

There is a short passage in the judgment of His Honour Judge Hacon in Edward Lifesciences -v- Boston Scientific 2017] EWHC 405 (Pat) (03 March 2017) that encapsulate the issues surrounding the assessment of expert evidence.

“Rarely, if ever, is an expert witness wholly objective by the time of the trial. Such is the effect of being part of a litigation team for which the focussed goal is, understandably, winning the argument. And, after all, there is a selection process.”

“No expert may be entirely objective but many are willing at least to give priority to assisting the court with accurate and helpful technical evidence.”

THE CASE

The dispute related to patents in relation to heart valves. Whether patents had been infringed and whether they were valid. This involved the judge assessing the evidence of the expert witnesses called by each part.

THE JUDGMENT

The Witnesses

1. I have already mentioned Boston’s clinical expert witness, Professor Georg Lutter. He is Professor of Cardiac Surgery at the University of Kiel and Head of the Department of Experimental Cardiac Surgery and the Heart Valve Replacement Department. Despite being a surgeon, Professor Lutter has carried out many TAVI procedures at Kiel. For most of these procedures Professor Lutter used Edwards’ Sapien 3 device, having implanted about 250 of these by the time of giving evidence.

2. My impression was that Professor Lutter was generally a good witness despite occasionally displaying what seemed to me to be a rather drawn out reluctance to accept matters of practice known at the priority date, matters made evident by contemporaneous documents.

3. Boston’s other expert was Professor James Moore. He is currently Professor of Biomedical engineering at Imperial College London. Professor Moore’s particular expertise is in the field of stents.

4. Professor Moore has given expert testimony in nine patent infringement cases in the United States, in five of which he was an expert on behalf of Boston. I mention this because, I regret to say, in the course of listening to Professor Moore I formed the impression that he has also developed what he might regard as an expertise in giving evidence. Professor Moore was extremely careful in giving his answers. I increasingly took the view that this was because his first priority was to avoid saying anything that might damage Boston’s case. Assisting the court with his honest views was only a secondary motivation, at best. This was not helpful. I do not suggest that Professor Moore was going out of his way to mislead the court. But if a witness prevaricates at length over any answer that might not help the position of his side, the court is unlikely to accord much weight to his evidence as a whole. There will always be a strong suspicion of persistent bias.

5. This must be put into perspective. Rarely, if ever, is an expert witness wholly objective by the time of the trial. Such is the effect of being part of a litigation team for which the focussed goal is, understandably, winning the argument. And, after all, there is a selection process. Nevertheless many experts find it possible to make appropriate concessions where their honest views require agreement with a point being put by counsel. No expert may be entirely objective but many are willing at least to give priority to assisting the court with accurate and helpful technical evidence.

6. This takes me to Edwards’ experts. Their expert clinician was Dr Nigel Buller. Dr Buller is a retired consultant cardiologist. Until 2008 he was Head of Interventional Cardiology at the Queen Elizabeth Hospital, Birmingham and the lead clinician for its cardiac catheterisation laboratories. During the course of his career Dr Buller developed an interest in interventional cardiology and had hands-on experience with the insertion of coronary stents. TAVI procedures were not used in the UK until 2008, a while after the priority date, by which time Dr Buller had stopped performing invasive procedures. He later received some training in TAVI at the New York Presbyterian Hospital in 2013.

7. Dr Buller, like Professor Moore, has experience of being an expert witness in several proceedings, both in this country and in the United States. There the comparison ends. I found Dr Buller to be an excellent witness. He gave clear and direct answers without undue delay whenever he was able to. My impression was that Dr Buller was occasionally susceptible to hindsight and liable to accord more creativity to the skilled person than was appropriate in law. This, though, is not a criticism, just an observation.

8. Edwards’ expert on biomechanical engineering was Professor John Fisher. He has been Professor of Mechanical Engineering at the University of Leeds since 1993 and is current Pro-Vice-Chancellor for Research at that university. He is also a director of four externally funded centres of research into medical engineering.

9. Professor Fisher did not claim any in-depth knowledge of TAVI procedures although he had read some of the commercial and academic literature in that field. He was a good witness so far as his evidence went.”