Dr Agnes Louise Johnston against GA and another (Court of Session)

Factual and Procedural Background

This appeal concerns whether a mental health tribunal is bound by an earlier tribunal decision regarding the same patient. The patient, referred to as GA, is subject to a compulsory treatment order and is in a specialist unit for an eating disorder. In May 2024, at the request of the responsible medical officer (RMO), a warrant was granted by Scottish Ministers under cross-border regulations for GA's transfer to an English hospital. This warrant was successfully appealed by GA and her named person (her father) in June 2024. Subsequently, the RMO sought a second warrant for the same transfer purpose, granted in September 2024, which was appealed to a differently constituted tribunal. In December 2024, the tribunal held a preliminary hearing to determine whether a further evidential hearing was necessary given the earlier decision. Applying the doctrine of res judicata, the tribunal granted the appeal, preventing the transfer. The present court was asked to set aside the December tribunal’s determination as legally erroneous on the basis that res judicata should not apply rigidly where circumstances may change and the patient's best interests are paramount.

Legal Issues Presented

1. Whether a mental health tribunal is bound by an earlier tribunal decision concerning the same patient.
2. To what extent the doctrine of res judicata applies in mental health tribunal proceedings, particularly where circumstances may have changed.
3. Whether the December tribunal erred in applying res judicata to refuse a further evidential hearing on the proposed transfer.

Arguments of the Parties

Responsible Medical Officer's Arguments

• Accepted that res judicata can apply in public law but not as strictly as in private law.
• Statutory framework and inquisitorial nature of the tribunal procedure support the appeal.
• Primary concern is the patient's best interests; technical evidential restrictions should not impede welfare.
• Children’s hearings system is not subject to res judicata for similar reasons.
• Not seeking to nullify the June decision but appealing a subsequent warrant based on different information.
• The June tribunal’s decision was not final for all time; genuinely new information justified further evidence.

GA and Her Father’s Arguments

• The earlier decision should be respected unless a good reason exists to revisit the issue.
• RMO had the opportunity to present the best case in June; no new evidence changed the case's complexion.
• Principles of res judicata resonate in permanence proceedings and require fresh evidence or material change.
• Repeated disputes harm the patient’s wellbeing and waste resources.
• No procedural requirement for a second tribunal to hear oral evidence.
• The specialist tribunal was entitled to conclude that the material did not justify another evidential hearing.

Table of Precedents Cited

Precedent	Rule or Principle Cited For	Application by the Court
R(Abidoye) v Secretary of State for the Home Department [2020] EWCA Civ 1425	Earlier decision final and binding absent legal justification or change of circumstances; fresh evidence must meet Ladd v Marshall test.	Referenced to explain the principles of res judicata and the need for fresh evidence to justify reopening the matter.
Ladd v Marshall [1954] 1 WLR 1489	Test for admitting fresh evidence: (i) could not have been used earlier, (ii) likely to influence outcome.	Used as a benchmark to assess whether new evidence justified re-examination by the tribunal.
RG v Glasgow City Council 2020 SC 1	Res judicata allows reliance on facts determined earlier; repeated litigation on same issue not tolerated.	Supported the tribunal’s case management power to refuse re-litigation absent significant new evidence.
Thrasyvoulou v Secretary of State for the Environment [1990] 2 AC 273	Res judicata applies beyond private law unless statutory framework indicates otherwise.	Confirmed the applicability of the doctrine in public law contexts including mental health tribunals.
R(Ex parte Momin Ali) v Secretary of State for the Home Department [1984] 1 WLR 663	Finality of litigation unless contrary to wider interests of justice.	Referenced to emphasize limits on reopening decided matters.
Secretary of State for the Home Department v TB (Jamaica) [2008] EWCA Civ 977	Subsequent administrative decisions cannot circumvent tribunal decisions absent good reason.	Supported the principle that mere disagreement does not justify reopening.
R(Von Brandenburg) v East London and The City Mental Health Trust [2004] 2 AC 280	Applicant must have information not known to tribunal that puts a significantly different complexion on the case.	Adopted to assess whether new evidence justified a new hearing.
Grahame v Secretary of State for Scotland 1951 SC 368	Public policy, equity, and common sense prevent repeated litigation on the same issue.	Supported the principle underlying the plea of res judicata.
C, Petitioner 2012 SLT 521	Example of res judicata in mental health tribunal jurisdiction decisions.	Illustrated application of res judicata in mental health tribunal context.
Rankin v Jack 2010 SC 642	Consideration of res noviter veniens ad notitiam (newly come to light evidence).	Referenced in relation to the test for admitting new evidence.
Adeboye (Andrews LJ Judgment)	Res judicata principles may apply but not with full rigour; fresh evidence must meet Ladd v Marshall tests.	Influenced tribunal’s approach to evidence and res judicata in this case.

Court's Reasoning and Analysis

The court recognized that the strict rules of res judicata applicable to adversarial private law claims cannot be fully applied to mental health tribunal decisions, which must focus on the patient's best interests as circumstances evolve. The June tribunal’s refusal of transfer was not final for all time and identified missing evidence that could have altered the outcome. The December tribunal properly assessed whether new evidence justified reopening the matter, concluding it did not meet the necessary threshold.

The December tribunal’s approach was not a rigid application of res judicata but a case management decision weighing the material’s significance. It avoided an overly technical approach, consistent with the primary concern for the patient’s welfare. The court found that the December tribunal correctly applied the principle that new evidence must place a significantly different complexion on the case compared to what was before the earlier tribunal. The new evidence did not address the significant concerns previously raised, and thus did not justify an evidential hearing.

The court noted the potential confusion caused by the term "res judicata" in this context but confirmed that the tribunal’s substantive examination of the evidence and its decision not to reopen the case was legally sound. The court also distinguished this case from other contexts where res judicata principles are more strictly applied, emphasizing the unique nature of mental health tribunal proceedings.

Holding and Implications

The court REFUSED THE APPEAL, holding that the December tribunal’s decision was not vitiated by any material error of law and was an outcome the tribunal was entitled to reach.

The direct effect of this decision is that the December tribunal’s determination, which prevented a further evidential hearing and thus the cross-border transfer of GA, remains in force. No new precedent altering the doctrine of res judicata in mental health tribunal proceedings was established; rather, the decision affirms the tribunal’s discretion to manage cases in a manner consistent with patient welfare and procedural fairness.