The Critical Importance of the Expert’s Independence

It seems that barely a few weeks go by between High Court judgments criticising the conduct of experts.

It is easy to fall into the trap of thinking that success in a clinical negligence case comes down to a battle between the experts instructed by each party. Whilst the individual merits of each expert’s opinion will be tested carefully by the Court, it is not for the expert to seek to persuade the judge to come round to their way of thinking or to side with the party instructing that expert.

However, as many will know, the expert’s primary duty is to assist the Court, from a position of independence, to come to a view on professional matters as applied to the facts of the case. It is for the court to determine the facts and for the expert to provide professional opinion on those facts.

It never ceases to amaze me how frequently these two issues of independence and experts deciding facts arise in relation to expert evidence.

One such recent judgment is that of Her Honour Judge Melissa Clarke in the case of Hodgson -v- (1) Dr Hammond and (2) Dr Dieleman [2025] EWHC 1261 (KB).

This case arises from the treatment that the claimant received from 2 GPs (Dr Hammond and Dr Dieleman) in relation to the investigation and further management of suspected pelvic inflammatory disease (PID).

My colleague, Alex Stutt, has recently written about this case in relation to the Judge’s application of the principles in Bolitho v City and Hackney Health Authority [1998] AC 232.

Essentially, the claimant’s allegations were that each GP ought to have recognised the risk that she was suffering with PID and thus should have performed or arranged for a pelvic examination to investigate further.

PID can have a very variable presentation with some patients presenting with symptoms such as severe abdominal pain and discharge, whereas other patients may present with relatively mild symptoms. However, the consequences of untreated PID can be potentially serious leading to problems such as chronic pain and difficulties with fertility. It is, therefore, essential that GPs have a low threshold for considering such a diagnosis and investigating.

In this case, both GP defendants accepted that, had a pelvic examination been undertaken or organised, it would have revealed findings that would have triggered further investigation, diagnosis and thus earlier treatment of PID. Instead, the claimant’s condition went undiagnosed for many months such that she developed a pelvic abscess, adhesions and required pelvic surgery including the removal of one fallopian tube.

The issues for the court to determine were thus restricted to matters of breach of duty of care on the part of each GP defendant. The key issue was whether each GP ought to have performed or organised a pelvic examination.

The claimant and each GP defendant instructed their own GP experts to advise on the standard of care provided by each GP defendant.

All experts were criticised by the judge.

The Case Against the First Defendant – Dr Hammond

In the weeks prior to the claimant’s consultation with Dr Hammond, she had been admitted to a local hospital with a presumed diagnosis of pyelonephritis (a kidney infection), but subsequent investigations suggested that that diagnosis was probably incorrect.

She had subsequently seen a colleague of Dr Hammond’s who had made a detailed note casting doubt on the diagnosis of pyelonephritis and raising the possibility of a pelvic infection. That colleague indicated that further investigation or examination would be required, but it was the bank holiday weekend, the claimant was preparing to go away and the time of the consultation was already late into the evening. That colleague therefore suggested an appointment a few days later with Dr Hammond.

Dr Hammond made a detailed note indicating that he had read the previous records and identified the risk of a pelvic infection but considered it to be resolving. The claimant was therefore sent away from the consultation with advice to return if her symptoms deteriorated.

At Trial, the experts agreed that a doctor should have a very low threshold for investigating pelvic infection because of the potential for serious ongoing problems if PID is missed and because the presentation can be very variable. One expert indicated that the risk of delayed diagnosis could be “catastrophic”. The expert instructed by Dr Hammond indicated that where PID is being considered, a pelvic examination, which includes both speculum and bimanual examination, is mandatory.

However, Dr Hammond’s expert then proceeded to advise that there would be a responsible body of GPs who would support not performing a pelvic examination at that consultation because:

1. The claimant had a quiet abdomen with no fever or tachycardia.
2. The vaginal discharge had improved following removal of a contraceptive coil.
3. Previous treatment (provided for pyelonephritis) would have had an effect (although this was not the standard treatment for PID).
4. A pelvic examination at that point was not indicated.
5. The safety netting advice given by Dr Hammond was correct.

It was clear from his factual evidence that Dr Hammond had been considering the possible diagnosis of PID.

However, in contrast to his advice that there should be a low threshold for further investigation, Dr Hammond’s expert also advised the court that a pelvic examination was not mandatory in this case.

The Judge held that there was a clear logical inconsistency between those positions and so this was an unusual case where Dr Hammond’s expert’s evidence was rejected on the basis of the principles in the well-known case of Bolitho -v- City and Hackney Health Authority 1998 AC232.

When challenged the expert then sought to describe the Claimant as not presenting with pelvic symptoms at the time of the consultation. He added that she had presented with a “dramatic improvement” and that she was “virtually back to normal”. The expert added that in his opinion, Dr Hammond had “done a good job in flagging up the possibility that PID had been missed” but that the patient was now better and that the treatment had got rid of the pain. The expert said that GP’s do not “go around unpicking things”.

However, in cross examination, the expert accepted that:

• the treatment had not got rid of the pain;
• that the claimant still had niggling abdominal pain; and
• that the treatment that the claimant had previously received (for pyelonephritis) was not standard treatment for PID and therefore, given the absence of investigations, it could not be known if that treatment would have been effective or had only partially treated and therefore masked the symptoms of suspected PID.

The expert appeared to place great emphasis on his view that any PID was resolving and thus required no further investigation, but this was in stark contrast to his earlier advice that the longer PID is left untreated the more likely a patient is to have fertility problems.

The expert then also advised the court that he was not convinced that the Claimant would have been symptomatic in any event, even if she had been examined. This was contrary to the agreed evidence of the causation experts, all of whom indicated that there would have been positive signs to elicit on examination.  This was also an issue on which the GP experts had already agreed to defer to other experts!

The Judge considered that Dr Hammond’s expert was seeking to explain away Dr Hammond’s actions, had therefore lost independence and was seeking to advocate for him. She gave little weight to his expert evidence.

In contrast, the claimant’s GP expert had provided a logical and coherent opinion as to the need for further investigation and examination. The Judge therefore found that the claimant had proved negligence against Dr Hammond.

The Case Against the Second Defendant – Dr Dieleman

The same issue fell to be considered in relation to Dr Dieleman, who had held a telephone consultation with the claimant five days after Dr Hammond’s consultation.

In his witness statement, Dr Dieleman stated at the outset that he had no recollection of the consultation with the claimant and that his evidence was based on the limited note that he had made and his usual practise.

A key issue in determining whether a pelvic examination ought to have been performed was whether the GP did or ought to have had the possibility of PID in mind at the time of the consultation.  Dr Dieleman’s evidence was inconsistent in this respect.

In his statement he also stated that:

• he was relying upon the previous diagnosis of pyelonephritis.
• he felt that at the time the claimant was getting better and the kidney infection was resolving,
• the blood tests were improving,
• the claimant reported no new or developing symptoms; and
• even if it had been PID he felt it was resolving.

He also indicated in his oral evidence that he had considered the previous records of his colleagues who had raised a possible diagnosis of PID.

Despite that he did not consider that the claimant should undergo a pelvic examination or that PID needed to be excluded as a differential diagnosis.

All of these assertions were held to be incompatible with the Dr Dieleman’s clear assertion in his statement that he had no recollection of the consultation.

This became a key stumbling block for Dr Dieleman’s expert. It became apparent that his expert had taken as fact Dr Dieleman’s purported recollection of the events of the telephone call and his thought process, despite the absence of a detailed note and Dr Dieleman’s clear written evidence that he had no recollection of the consultation.

Of course, it is for the court to make findings of fact, not the expert.

When it was put to his expert that Dr Dieleman had no recollection of the consultation and thus that much if not all of his factual evidence to ought to be disregarded, the expert appeared to persist in relying on Dr Dieleman’s assertion that the claimant’s condition was resolving and that he had in mind pyelonephritis at the time of the consultation.

Dr Dieleman’s expert was reluctant to move from that position, but on further cross examination, the expert eventually had to accept that Dr Dieleman probably did or ought to have had in had in mind a diagnosis of PID.

This effectively undermined Dr Dieleman’s defence and the Claimant therefore succeeded against Dr Dieleman as well.

This case clearly illustrates common problems that continue to emerge with expert evidence. It is fortunate that episodes of experts becoming too closely aligned with their instructing parties’ positions are rare. Nevertheless, in my own experience I have encountered experts instructed my opponent who have sought to advocate for their client.  Their evidence tends to be disregarded by the Judge.

Perhaps more common is the problem of experts making factual findings where there are disputed factual accounts or inconsistencies in the factual evidence. Experts sometimes appear to be tempted to find a means of reconciling all of the evidence so as to produce a single factual account, when, in reality, different parties recall different factual accounts.  In such circumstances, the expert should be providing their opinion on each potential factual scenario.  Failure to do so usually leads to further problems.

It is essential that experts remember (or are perhaps reminded) that it is the Judge’s role to make findings of fact and that the expert’s role is to advise the Court on matters of professional opinion based on those facts.

If you have any questions contact our expert team on 020 7940 4060 or send us an email at mail@anthonygold.co.uk.