GUIDES
A retrospective opinion may be unable to reach a firm conclusion where records are incomplete, capacity fluctuated or the relevant moment was not documented. It should distinguish evidence from inference and explain uncertainty without predicting the court’s decision.
Author: Nellie Supports Ltd
Publication Date: 15/05/2026
Key v Key [2010] EWHC 408 (Ch).
Copyright © 2026 Nellie Supports Ltd. All rights reserved.
This article is made available for general information, education and professional reference. It may be downloaded, printed and shared for non-commercial purposes, provided that it is reproduced in full, is not altered in any way, and is properly cited as the work of Nellie Supports Ltd. This material must not be edited, adapted, sold, republished, incorporated into commercial products, or used for commercial training, assessment, report-writing or advisory services without prior written permission from Nellie Supports Ltd.
This article does not constitute legal advice, clinical advice or a substitute for a decision-specific professional assessment. Where legislation, government guidance, court forms or external professional materials are referred to, those materials remain subject to their own copyright, licensing and re-use terms.
A retrospective opinion may be unable to reach a firm conclusion where records are incomplete, capacity fluctuated or the relevant moment was not documented. It should distinguish evidence from inference and explain uncertainty without predicting the court’s decision. This guide covers the relevant evidence, support, process and limits in England and Wales.
A retrospective opinion may be unable to reach a firm conclusion where records are incomplete, capacity fluctuated or the relevant moment was not documented. It should distinguish evidence from inference and explain uncertainty without predicting the court’s decision. Some experts may have known the person, and some records were expressly about capacity. Explain the actual evidence in this case rather than assume that all historical records have the same limitations.
The central limitation is that the opinion concerns a past moment that may not be fully documented. Define what the surviving material can reasonably establish. The value of further work depends on whether it could answer a material gap, not on whether it might strengthen a preferred case.
Identify why each record was made and what it actually addresses. Clinical and care notes may not assess the decision, while a contemporaneous capacity report or solicitor’s note may do so directly. Silence about cognition does not alone prove either ability or inability.
Name missing periods, documents and unrecorded meetings. Any inference must rest on identified evidence, such as the condition’s course, and should be labelled as inference. The applicable legal presumption and burden depend on the question; do not import the MCA burden unchanged into every probate dispute.
A later diagnosis may illuminate an earlier impairment if the evidence supports that inference. It does not necessarily establish onset or the person’s decision-making abilities on the material date. An outcome now regarded as foolish or unfair also does not by itself prove earlier incapacity.
Assess witness evidence for opportunity to observe, detail, timing, consistency and potential interest. Memory may be affected by time or later events, but a late account is not automatically unreliable or merely evidence of a current belief. Explain the particular reasons for accepting or questioning it.
Fluctuation, an acute episode, limited records or a private decision may make reconstruction difficult. State how those features affect this opinion and whether other sources could help. A firm conclusion should not be supplied where the record does not support one.
Explain whether the evidence supports the opinion to the relevant standard, points towards an answer with uncertainty or is insufficient for a conclusion. The court decides the legal issue and weight of evidence; an expert should not claim to predict the result or decide the legal merits.
Expect dates and provenance, the correct decision and test, material gaps, contrary evidence and labelled inferences. Ask focused questions about uncertainty and whether further records would matter. Legal advice is needed on burden, procedure and the next step in any dispute.
The strength of a retrospective opinion depends on the relevant evidence and the reasoning it can support. Recognise the limits of records, memory and inference and explain uncertainty openly. Candour makes the opinion more useful without guaranteeing that a court will accept it.
No. A diagnosis does not establish lack of capacity. For a decision under the Mental Capacity Act, consider the relevant information and practicable support, then assess understanding, retention, use or weighing and communication by any means. Any inability must be caused by an impairment of, or disturbance in the functioning of, the mind or brain. Will-making has its own legal test.
The complete surviving record, including the unhelpful parts: an opinion built only on selected favourable documents is exposed the moment the other side serves the rest. Disclosure of gaps and contrary entries is what makes the confident parts credible.
A proportionate review may assist even where the record is incomplete, but a full report is not always justified. Ask what question it could answer, what remains unknowable and whether further evidence is likely to change the position.
The related guides below provide further explanation of the decisions, evidence and legal processes discussed here.
Ask the expert which gaps matter, which inferences are justified and how strongly the evidence supports the opinion. Legal advice is needed on the applicable burden of proof and whether the evidence warrants further steps.
A GOOD PLACE TO START
Tell us what is happening and what you need help with. We will listen, explain the options and help you find the right starting point.