“Qualified Finality” — The Limited Reach of Res Judicata in Scottish Mental-Health Tribunal Appeals

1. Introduction

In Dr Agnes Louise Johnston v GA and another ([2025] CSIH 18) the Inner House of the Court of Session was asked to decide whether, and to what extent, a Mental Health Tribunal (MHTS) is bound by its own previous refusal to authorise a cross-border transfer of a patient.

The essential facts are straightforward yet procedurally complex:

• Patient: GA, a young adult suffering from a severe eating disorder, detained under a Compulsory Treatment Order (CTO) in Scotland.
• Clinician/Appellant: Dr Agnes Johnston, GA’s Responsible Medical Officer (RMO), who considered transfer to a specialist unit in London necessary.
• First tribunal (June 2024): Refused to authorise transfer, highlighting nine areas of concern about safety, distance from family, and inadequately investigated benefits.
• Second warrant (Sept 2024): The Scottish Ministers issued a fresh warrant based on additional information. A differently constituted tribunal heard preliminary argument in December 2024 and, invoking res judicata, declined to rehear the matter.
• Appeal: Dr Johnston contended that the December tribunal erred in law by treating the earlier decision as binding in circumstances where conditions and evidence can evolve rapidly.

2. Summary of the Judgment

Delivering the Opinion of the Court, Lord Malcolm (with the Lord Justice Clerk and Lord Armstrong concurring) dismissed the appeal. The Court held:

• Strict, private-law rules of res judicata do not apply wholesale to MHTS proceedings, but the principle of finality remains relevant.
• A second application will only progress where new material “puts a significantly different complexion on the case”.
• The December tribunal lawfully exercised its case-management powers in weighing the fresh material and deciding it did not meet that threshold; no error of law arose.

3. Analytical Commentary

3.1 Precedents Cited and Their Influence

1. Thrasyvoulou v Secretary of State for the Environment [1990] 2 AC 273
   Established that res judicata can apply to administrative decisions unless legislation provides otherwise. Provided doctrinal anchor for considering finality in public-law contexts.
2. R (Ex parte Momin Ali) [1984] 1 WLR 663
   Confirmed that finality must yield where it would be contrary to the wider interests of justice. The Court drew on this to underline the need for flexibility in mental-health matters.
3. Secretary of State v TB (Jamaica) [2008] EWCA Civ 977 and R (von Brandenburg) [2004] 2 AC 280
   Immigration authorities cannot circumvent tribunal decisions absent genuinely new evidence or changed circumstances. Lord Bingham’s “significantly different complexion” test in von Brandenburg became the Court’s preferred formulation.
4. R (Abidoye) [2020] EWCA Civ 1425
   Discussed a “softer” application of res judicata in public-law cases and imported the Ladd v Marshall test. The Court of Session distinguished, noting the materially different statutory frameworks.
5. Scottish authorities on res noviter: Rankin v Jack 2010 SC 642 and RG v Glasgow City Council 2020 SC 1
   Gave guidance on when previously determined facts can or cannot be revisited in child-care and permanence proceedings, providing domestic analogies for the MHTS context.

3.2 Legal Reasoning of the Court

1. Statutory Purpose Supersedes Procedural Finality. MHTS decisions are forward-looking, welfare-centred, and inquisitorial. Unlike a civil judgment determining private rights, they cannot purport to bind the future indefinitely because a patient’s condition and available treatments may evolve.
2. “Qualified Finality”. While absolute finality is inappropriate, endless relitigation is equally undesirable. The Court adopted an intermediate position:
   “If the material now relied upon does not put a significantly different complexion on the case, an evidential rehearing is unnecessary.”
   This balances patient welfare with judicial economy.
3. Rejection of the Strict Ladd v Marshall Gateway. The Court thought it too rigid to exclude evidence that could have been adduced earlier. What matters is its materiality and whether it responds to the original tribunal’s concerns.
4. Case-Management Discretion. A specialist tribunal may scrutinise proffered documents at a preliminary stage and decide—without oral evidence—that nothing new of substance has emerged. That choice, absent error of principle, is unimpeachable on appeal.

3.3 Potential Impact

• Guidance for Practitioners. RMOs and Health Boards must ensure that fresh applications demonstrably tackle the flaws identified in earlier refusals.
• Tribunal Procedure. MHTS panels can safely refuse a rehearing where new material is insubstantial, invoking “qualified finality” rather than full res judicata.
• Cross-Border Transfers. Scottish Ministers should verify that each warrant is grounded on genuinely upgraded information, reducing futile litigation.
• Broader Administrative Law. The decision may influence other specialist decision-makers (e.g., children’s hearings, parole board) when balancing welfare dynamics with procedural economy.

4. Complex Concepts Simplified

• Res Judicata: Latin for “a matter judged”; the rule that once a dispute is finally decided it cannot be litigated again between the same parties.
• Qualified Finality: A softer version of res judicata recognised in welfare-based tribunals; repeat applications are barred unless new, material circumstances arise.
• Res Noviter Veniens ad Notitiam: Scots law counterpart of Ladd v Marshall; allows introduction of evidence that genuinely could not be led earlier and would probably have changed the outcome.
• Compulsory Treatment Order (CTO): Court-authorised detention and treatment of a patient with mental disorder under Scottish legislation.
• Responsible Medical Officer (RMO): Senior clinician tasked with the patient’s care and decisions about compulsory measures.
• Cross-Border Regulations: Statutory provisions permitting transfer of patients between jurisdictions within the UK for treatment.

5. Conclusion

The Court of Session’s ruling in Johnston v GA crystallises a nuanced doctrine of “qualified finality” for mental-health tribunals: strict res judicata is inappropriate, yet repetitive litigation is curtailed. The governing question is pragmatic—does the new material cure the deficiencies previously identified and present the patient’s best interests in a new light? If not, the tribunal is entitled, without further evidence, to close the door.

For mental-health jurisprudence in Scotland, the decision supplies much-needed clarity, balancing evolving clinical realities against the imperative for finality and resource stewardship. Future litigants must therefore concentrate on substantive, not merely incremental, change when seeking to revisit earlier tribunal determinations.