Morgan v Abertawe Bro Morgannwg University Local Health Board

The Employment Appeal Tribunal held that Employment Tribunals should apply the CPR test that expert evidence is only admissible if it is "reasonably required" to resolve the issue. The tribunal must first decide, in principle, whether expert evidence should be allowed. If allowed, the tribunal must then give tailored directions on form, scope and procedure for expert evidence.

Where an issue turns primarily on medical understanding of history, aetiology or counterfactual prognosis, expert medical evidence is likely to be reasonably required and should be permitted in principle.

The appellant, a nurse with a long-term mental-health disability, had previously succeeded on liability for a failure to make reasonable adjustments by redeployment between April and August 2011. The remedy stage required consideration of whether, on the counterfactual that redeployment had occurred, her health would have deteriorated as it did.

The Employment Tribunal refused permission to admit expert psychiatric evidence after receiving a paper-only report. The appellant appealed that case-management decision to the EAT. The EAT reviewed the applicable guidance in [2001] IRLR 324 and the CPR approach to expert evidence, and considered whether the tribunal misdirected itself and reached an impermissible conclusion.

The central question was whether expert medical evidence on the counterfactual prognosis was, in principle, reasonably required to decide remedy.

1. The appeal is allowed. The Employment Tribunal erred in procedure and substance in refusing permission for expert medical evidence.
2. The correct threshold test for permission is that expert evidence should be restricted to that which is reasonably required to resolve the proceedings, following the approach in [2001] IRLR 324 and by analogy with CPR 35.1. The overriding objective informs but does not replace that test. (See discussion and conclusions.)
3. The tribunal should adopt a two-stage approach. First decide, in principle, whether expert evidence should be permitted on the particular issue. If the answer is yes, give directions about scope, format and procedure for expert evidence, drawing on the guidance in [2001] IRLR 324 (joint expert preferred, timetable, questions, meetings, etc.).
4. The tribunal took the wrong procedural course by making the obtaining of a paper-only report a condition precedent and then deciding the permission question by reference to that limited report. That approach was unfair and incorrect in principle.
5. The judge misjudged the content and utility of the paper report. It was not plainly irrelevant or of no assistance on the causation/counterfactual question. Where an expert's meaning is unclear, the tribunal should normally allow testing by questions, further reports or at hearing rather than exclude the evidence in advance.
6. On the facts, the question whether redeployment would have changed the subsequent course of a mental-health condition involves matters of history, aetiology and prognosis. Those matters are inherently suited to expert medical evidence and, in this case, expert evidence is reasonably required. The EAT substituted the tribunal's decision and directed that expert medical evidence be permitted in principle.
7. The matter is remitted to the Employment Tribunal to give appropriate directions for the obtaining, exchange and use of expert evidence at the Remedy Hearing. The EAT did not itself give detailed substantive directions but substituted the threshold decision permitting expert evidence.

• Employment Appeal Tribunal: Appeal heard and decision allowing the appeal; substituted a decision permitting expert medical evidence (12 September 2019).
• Court of Appeal: Earlier decision of 28 March 2018 addressed liability and remitted parts of the remedy questions to the Employment Tribunal (noted in judgment).
• Employment Tribunal: Earlier liability hearings and reserved decisions (January–February 2013; February 2015) found failure to make reasonable adjustments for April–August 2011; subsequent remedy hearing directions challenged on appeal.