Insights
When Expert Evidence Goes Wrong – The 5 Common Mistakes – Part 3
Part 3: The Expert Who Answers the Wrong Question
An expert may produce a technically sophisticated report but still fail to assist the court. The problem may not lie in the quality of the analysis, but in the question the expert has chosen to answer.
In complex disputes, the boundaries between technical opinion, factual determination and legal argument can easily become blurred. An expert may begin by addressing matters properly within their expertise but gradually move into questions that should be answered by factual witnesses, lawyers or ultimately the court.
This can often result in an expert opinion that is largely irrelevant to the decision the court actually has to make.
The importance of the question
The starting point for any expert instruction is to identify precisely what the expert is being asked to determine. That sounds straightforward, but in practice instructions can be broad and may combine technical, factual and legal issues.
The difficulty arises when those different questions are not clearly separated. The following distinctions are fundamental:
- Explaining whether conduct is consistent with market practice is not the same as deciding why a particular person acted as they did.
- Explaining the economic effect of a transaction is not the same as determining its legal effect.
- Assessing whether an explanation is commercially plausible is not the same as deciding whether the witness giving that explanation is truthful.
Failing to recognise these can lead an expert beyond their proper role and into matters that are ultimately for the court to decide.
Fact, inference and opinion
A useful discipline is to distinguish clearly between fact, inference and expert opinion.
- Facts are established by the evidence and ultimately determined by the court where they are disputed.
- Inferences may be drawn from those facts, but some inferences fall properly within the expert’s specialist knowledge while others do not.
- Expert opinion should be confined to matters where specialist expertise is required to assist the court.
For example, an expert may properly explain that a particular trading pattern would be unusual in normal market conditions. The expert may also explain the commercial reasons why such a pattern might occur. It is a different matter to conclude that a trader must therefore have intended to deceive another party; that is for the court to decide.
When technical language masks a factual conclusion
One of the difficulties is that a factual conclusion can sometimes be presented in technical language and therefore appear to be expert evidence.
An expert may say that a transaction had “no commercial rationale”, when what is really meant is that the expert does not accept the explanation given by the factual witnesses. The expert may describe conduct as “artificial”, “contrived” or “not genuine” without clearly identifying whether those terms describe a technical feature of the transaction or a conclusion about the intentions of the parties. In other words, the use of specialist terminology does not turn a factual or legal judgment into an expert opinion.
Intention and state of mind
Experts should be particularly careful when addressing intention.
A specialist may be able to explain the likely economic consequences of particular conduct or whether the conduct is consistent with a stated objective. They may also identify evidence that appears inconsistent with the explanation given, which can be highly useful to the court.
But there is an important difference between saying:
“The conduct is inconsistent with the stated commercial objective.”
and saying:
“The individual did not genuinely hold that commercial objective.”
The first may be an expert opinion based on specialist analysis, the second is a conclusion about a person’s state of mind.
The expert should not cross that boundary merely because the technical analysis makes one explanation appear more or less likely.
Credibility
Experts may encounter factual accounts that conflict with documents, market practice or their own technical analysis. They should identify those conflicts and explain why an account may be difficult to reconcile with the objective evidence.
They should not, however, decide whether a witness is truthful, that is for the court to decide.
Questions of law
An expert may also stray into legal conclusions, which can happen particularly where the subject matter is closely connected with regulation, tax, accounting or contractual interpretation. An expert with extensive industry experience may be very familiar with the relevant legal framework which may form an important part of the background to the expert’s analysis. But familiarity with the law does not mean that the expert should decide the legal issue before the court.
An expert may explain market practice under a particular regulatory regime, or how market participants would normally understand or operate under a contractual structure. They may also identify the economic consequences of applying one interpretation rather than another.
However, the legal meaning of the statute, regulation or contract remains a matter for the court.
An expert opinion should therefore avoid simply adopting a legal conclusion and presenting it as specialist evidence.
The danger of answering the pleadings
A report can become too closely aligned with the pleadings, which advance the parties’ legal and factual cases but do not necessarily define the proper scope of expert opinion.
A pleaded allegation may combine issues requiring expert analysis with disputed facts, legal interpretation or intention. The expert should separate those elements rather than simply state that the allegation is “correct” or “incorrect”. Otherwise, the report risks becoming a submission rather than expert evidence.
The expert should identify the limit
A strong expert report should make clear not only what the expert can say, but also what they cannot say.
That may require wording such as:
“My opinion is limited to the commercial effect of the transaction.”
“I can comment on whether the conduct was consistent with normal market practice, but I cannot determine the intention of the individuals involved.”
“My conclusion assumes that the factual evidence identified above is accepted by the court.”
“This is ultimately a question of contractual interpretation and therefore outside my expert opinion.”
Such limitations do not weaken the report, they demonstrate that the expert understands the boundaries of their role.
A useful test
Before answering a question, an expert should ask:
- Does this question genuinely require my specialist expertise?
- Am I expressing an opinion or deciding a disputed fact?
- Am I being asked to determine someone’s intention or state of mind?
- Does my conclusion depend on believing one witness rather than another?
- Am I interpreting the law rather than explaining the technical context in which it operates?
- Am I answering the expert issue or simply agreeing with a proposition in the pleadings?
- Can I identify clearly where my opinion ends and the court’s decision begins?
These questions should remain in mind throughout the preparation of the report.
The value of discipline
The strongest expert evidence is not necessarily the evidence that reaches the furthest. It is the evidence that stays within the expert’s proper field and assists the court on the matters where specialist knowledge is genuinely required.
An expert who answers the wrong question risks becoming irrelevant or, worse, an advocate. The value lies in providing clear, independent technical opinion while leaving the court to decide the issues that are properly its own.
srb@objectivus.com
+44 (0) 7990 584 285