Witness evidence

Professional negligence claims are often heavily swayed by witness evidence, which is by its nature inherently uncertain. You can never quite predict what a witness will say or how a court will react.

For insurers with conduct of pre-action claims, early investigation of witness evidence can significantly affect the analysis of litigation risk and resolution strategy.

A recent case – GH v The Catholic Child Welfare Society [2016] - has provided a useful summary of the framework the courts apply to assess the reliability of witness evidence.

GH v The Catholic Child Welfare Society [2016] (GH)

GH was one of eight lead cases in a group of 249 claims by former attendees of a care home and school for boys with serious behavioural problems. The claimants sought damages from the organisations which ran the school for alleged physical and sexual abuse by its teachers and other staff. GH’s claim related to his stay at the school between March 1985 and June 1986.

In such claims, where there were likely to only be two direct witnesses to the material events, the credibility of competing witnesses was crucial. The passage of time, unavailability of witnesses and limited documentary evidence all also made the testimony of GH crucial. His Honour Judge Mark Gosnell summarised the key considerations for assessing credibility as follows.

Firstly, HHJ Gosnell quoted the test suggested in an article by Mr Justice Bingham (as he was then):

“(1) the consistency of the witness's evidence with what is agreed, or clearly shown by other evidence, to have occurred;
(2) the internal consistency of the witness's evidence;
(3) consistency with what the witness has said or deposed on other occasions;
(4) the credit of the witness in relation to matters not germane to the litigation;
(5) the demeanour of the witness."

Mr Justice Bingham had emphasised that the first three considerations were the most reliable. He said the fourth test was more arguable and a witnesses’ demeanour should ordinarily be distrusted.

HHJ Gosnell then went on to quote Goff LJ in The Ocean Frost [1985]: “It is frequently very difficult to tell whether a witness is telling the truth or not; and where there is a conflict of evidence …, reference to the objective facts and documents, references to the witness' motives and to the overall probabilities can be of very great assistance to a Judge in ascertaining the truth."

Finally, HHJ Gosnell quoted at length the comments on modern academic thinking on memory made by Mr Justice Leggatt in Gestmin SGPS v Credit Suisse [2013]:

One of the most important lessons of such research is that … we are not aware of the extent to which our … memories are unreliable … . Two common (and related) errors are to suppose: (1) that the stronger and more vivid is our feeling or experience of recollection, the more likely the recollection is to be accurate; and (2) that the more confident another person is in their recollection, the more likely their recollection is to be accurate. …

"… psychological research has demonstrated that memories are fluid and malleable, being constantly rewritten whenever they are retrieved. …

… memory is particularly vulnerable to interference and alteration when a person is presented with new information or suggestions about an event in circumstances where his or her memory of it is already weak due to the passage of time.”

Mr Justice Leggatt went on to cite the following influences on witnesses in the course of litigation:

  • Witnesses often have a stake in the outcome of the litigation, have a sense of loyalty towards a party or simply want to give a good impression in public.
  • Statements may be drafted by a party’s solicitor and after the witness’ memory has been refreshed by reading documents and made aware of the issues by reading the statements of case.
  • The witness will then be asked to review his/her statement before trial, which causes the witness’ memory to be based increasingly on this later interpretation rather than the original experience.

Mr Justice Leggatt concluded that:

“the best approach … [is] to place little if any reliance at all on witnesses' recollections of what was said in meetings and conversations, and to base factual findings on inferences drawn from the documentary evidence and known or probable facts. This does not mean that oral testimony serves no useful purpose… . But its value lies largely … in the opportunity … to subject the documentary record to critical scrutiny and to gauge the personality, motivations and working practices of a witness … .”
Taking these considerations into account and weighing up the inconsistencies in GH’s evidence, HHJ Gosnell found he was not a reliable witness and that his allegations of abuse could not be proven.


Professional negligence claims often follow the same formula:
(a) I, the claimant, should have been advised in such a way.
(b) I was not advised in that way.
(c) Had I been advised in that way I would have followed that advice
(d) I would have benefitted from this and avoided that.

Proving and disproving the hypothetical statements at (b)-(d) usually depends on witness evidence from the claimant and from the defendant professional.

Insurers often handle claims pre-action and therefore can have a considerable impact on the collection and assessment of witness evidence. Given Leggatt J’s warnings about how memories can be influenced and reinforced, the initial steps taken by insurers can be key.

Some steps we can take to obtain clean and reliable evidence are as follows:

  1. Conduct an initial telephone call before the witness has the benefit of refreshing their memory by reviewing the documents and applying cognitive interview techniques. Identify and document any inconsistencies between the witness’ recollection and the documentary evidence.
  2. Provide the witness with underlying documents, but not the statements of case, to review in advance of a further discussion.
  3. Conduct a second interview and put inconsistencies to the witness. Make a careful note of the evidence.


It is often said that a particular person will or won’t “make a good witness”, but what does this mean? It seems clear that consistency with documentary evidence and previous statements, as well as internal consistency, will be critical. A witness’ demeanour or past conduct will be less important. Accordingly, it is possible for one’s personal impression of a witness to be misleading; a witness’ account may lack detail due to the passage of time and they may seem shifty, but if their account is also simple and consistent it may carry great weight.
An early assessment of a witness’ recollection, consistency in recollection and consistency with the documents is key. Initial interviews by insurers acting pre-action will provide a strong platform with which to evaluate the strength of the claim. Similarly, a Letter of Response is a good opportunity to (a) point out the inconsistencies between the hypothetical case stated by the claimant in the Letter of Claim, and (b) demand clarification of the claimant’s case so that further inconsistencies can be identified.