Coherent Reasons, Comparators and the Burden of Proof in Sex Discrimination Claims: Armagh City, Banbridge and Craigavon Borough Council v O'Neill [2025] NICA 61

1. Introduction

This Court of Appeal decision addresses a familiar, but often mishandled, problem in employment discrimination law: how tribunals should structure and reason their decisions in sex discrimination cases involving:

fixed-term contracts and alleged failure to make them permanent,
workplace restructurings and “matching/assimilation” exercises, and
reliance on both actual and hypothetical comparators.

Louis O’Neill, a male employee of Armagh City, Banbridge and Craigavon Borough Council, claimed sex discrimination contrary to the Sex Discrimination (Northern Ireland) Order 1976 (“SDO 1976”). His claim arose from the Council’s decision not to make his Corporate Planning Manager (“CPM”) role permanent, to terminate his fixed-term secondment after 3.5 years, and to redeploy him back to a lower‑graded substantive role, while a series of female colleagues were retained, “matched” or “assimilated” into new or permanent posts.

The Employment Tribunal (“the Tribunal”) upheld his complaint, essentially on the basis that a hypothetical female comparator would have been treated more favourably, that the workplace was overwhelmingly female, and that the Council had provided no satisfactory explanation for failing to extend his contract to the point where it would have become permanent. The Council appealed.

The Court of Appeal (McCloskey LJ, with Colton LJ and Kinney J agreeing) allowed the appeal, reversed the Tribunal’s decision, and remitted the case to a differently constituted tribunal. In doing so, the court re‑emphasised a set of core principles:

the need for clear, issue‑linked findings of fact;
the correct use of statutory and hypothetical comparators;
the proper operation of the two‑stage burden of proof in discrimination cases; and
the obligation to grapple explicitly with non‑discriminatory explanations advanced by the employer.

The decision does not change the substantive law of sex discrimination. Its importance lies in clarifying how tribunals must express and structure their reasoning, and in reaffirming the discipline required when moving from background grievances to legally sustainable inferences of discriminatory treatment.

2. Summary of the Judgment

2.1 Parties and procedural posture

Appellant: Armagh City, Banbridge and Craigavon Borough Council.
Respondent: Louis O’Neill, claimant before the Tribunal.
Forum: Appeal from the Industrial/Employment Tribunal to the Court of Appeal in Northern Ireland.
Outcome: Appeal allowed; Tribunal’s liability decision set aside; case remitted to a differently constituted Tribunal for a fresh hearing.

2.2 Factual background (in brief)

Mr O’Neill began as a Development Officer in 2006, later becoming Community Renewal Manager (“CRM”) on a fixed‑term basis, which was eventually made permanent in 2017. In January 2019 he took up a temporary fixed-term secondment as a Corporate Planning Manager (“CPM”) in the Community Planning Department (“CPD”), one of three Tier 4 managers; the other two were female. After he had taken up that temporary role, another, permanent CPM post was vacated by a female employee (“DG”) but was not advertised or offered to him.

Over the next three years his CPM contract was extended multiple times, ultimately expiring in mid‑2022. During that period the Council undertook structural reorganisations, including:

the dissolution of the Regeneration Department (“RD”),
the transfer of a female manager (“LO”) into the CPD,
the creation of a new Place and Strategic Projects Manager (“PSPM”) role,
the creation of new posts at officer level (e.g. “CPEO” and “PO”) into which female staff (“MM” and “EO”) were “assimilated” or “matched” following the restructuring.

In July 2022, Mr O’Neill’s CPM secondment ended and he reverted to his CRM substantive post on less favourable terms. He complained that, unlike him, female colleagues were redeployed or matched into new or permanent posts and that his CPM role was effectively dismantled and its functions allocated to women. Having exhausted internal grievances, he brought a Tribunal claim alleging sex discrimination.

2.3 The claimant’s core allegations

The Tribunal distilled nine particularised allegations of unlawful discrimination (para [11]), including:

failure to offer him the vacant permanent CPM role when DG left (11(a));
failure to explain that his CPM role could become his substantive post with redeployment rights if later withdrawn (11(b));
failure to consult adequately about the end of his CPM role, in contrast with consultations afforded to LO and EO when their posts were at risk (11(c));
dismantling his CPM role and reallocating its responsibilities to female colleagues, including LO and EO (11(d));
terminating his CPM role and restoring him to the CRM post, amounting to an effective demotion (11(e));
failure to create a new permanent post for him when the CPM role ended, contrasted with the creation of the PSPM role for LO (11(f));
provision of new posts for EO and MM (11(g));
assimilation of another employee, DS, into permanent and seconded posts (11(h));
failure to make his CPM secondment permanent after two years, allegedly contrary to an LGRJF Circular of July 2014 (11(i)).

The overarching theme was that male Mr O’Neill had been treated less favourably than female colleagues in the handling of fixed‑term roles, restructurings and redeployments.

2.4 The Council’s defence

The Council’s central case (para [10]) was that:

the CPM role was always temporary and subject to funding; his fixed‑term CPM contract simply expired and was not renewed;
a legitimate and wide‑ranging restructuring exercise led to the dissolution of the RD, with LO being offered the PSPM role as “suitable alternative employment” following the closure of her department;
MM and EO were both in posts that were extinguished during restructuring, and they were assimilated into new roles (CPEO and PO respectively) similar to their former roles;
by contrast, Mr O’Neill’s substantive department (where his CRM post sat) was not dissolved, so there was no question of “redistribution” or “assimilation” in the same sense;
accordingly, his circumstances were materially different from those of his alleged comparators, and thus they were not valid statutory comparators.

2.5 The Tribunal’s decision

The Tribunal accepted that the statutory (actual) comparators relied on by the claimant were not in the same or not materially different circumstances. Nevertheless, it found that:

a hypothetical female comparator in a seconded role, with a funded substantive post elsewhere, would have been treated more favourably (para [13](ii));
female colleagues had been moved “in a positive direction” (through suitable alternative employment or assimilation) whereas Mr O’Neill alone was returned to a less favourable role when his CPM contract ended (para [13](iii));
the working environment was “overwhelmingly female” and the Council’s evidence was “incohesive, confusing and difficult to collate” (para [13](i));
there was “no satisfactory evidence” that his CPM contract could not have been extended to four years to make him permanent (para [13](iii)).

The Tribunal held that the claimant had proved facts from which, absent explanation, discrimination could be inferred. It therefore shifted the burden of proof to the Council under Article 63A SDO 1976, found the Council’s explanation inadequate, and concluded that Mr O’Neill had been unlawfully discriminated against on grounds of sex (para [13](iii)).

2.6 Grounds of appeal

The Council challenged the judgment on three primary grounds (para [14]):

The Tribunal erred in law in holding that the burden of proof had shifted to the Council under Articles 3 and 63A SDO 1976 because the claimant had not established a prima facie case of discrimination (14(i)).
Having found that the claimant’s comparators were not in materially similar circumstances, the Tribunal erred in giving weight to their treatment in assessing discrimination (14(ii)).
Alternatively, if the burden had shifted, the Tribunal erred in ignoring (or inadequately analysing) the Council’s non‑discriminatory explanations: that Mr O’Neill was on a temporary fixed‑term contract and his role ended in the context of restructuring (14(iii)).

2.7 The Court of Appeal’s decision

The Court allowed the appeal. Its key conclusions (paras [21]–[22]) were:

The Tribunal’s “Findings of Fact” section was inadequately structured; it mixed narrative and evidence and did not link specific findings to the nine pleaded particulars of discrimination (21(i)).
The criticism of the Council’s evidence as “incohesive” and “confusing” lacked concrete detail or supporting factual findings (21(ii)).
The conclusion that a hypothetical female comparator would have been treated more favourably was “purely conclusionary” and unspecified: the Tribunal did not explain in what respects she would have been favoured (21(iii)).
The Tribunal made no findings about the specific discriminatory decision, the decision‑maker, or what actuated that decision – i.e. the “why” question central to discrimination analysis (21(iv)).
Having found that actual comparators were not in similar or materially similar circumstances, the Tribunal erred in law in then treating them as if they were valid statutory comparators for the purpose of its reasoning (21(v)).
The Council had advanced two evident non‑discriminatory reasons for the impugned conduct – the expiry of a fixed-term contract and a legitimate restructuring exercise – and the Tribunal failed “squarely” to engage with these reasons at both the burden-of-proof and substantive stages (21(vi)).

Because these were errors of law going to the heart of the discrimination analysis, the Tribunal’s decision was held to be “unsustainable in law” (22). The Court did not substitute its own finding on liability; instead it remitted the case to a differently constituted tribunal under section 38(1)(a)–(b) of the Judicature (NI) Act 1978.

3. Precedents and Authorities Cited

3.1 Shamoon v Chief Constable of the RUC

The court drew heavily on Shamoon v Chief Constable of the RUC [2003] NI 174 (House of Lords) for methodological guidance in discrimination cases (para [17]–[19]).

First, McCloskey LJ reminded appellate courts that although they should be cautious about disturbing tribunals’ factual findings, inadequately reasoned decisions are vulnerable to challenge. He referred to Lord Hope’s emphasis on appellate restraint, and Lord Hutton’s observation that insufficient reasoning can itself constitute an error of law (para [17]).

Second, the judgment quoted Lord Nicholls’ key warnings:

“the less favourable treatment issue is incapable of being decided without deciding the reason why issue. And the decision on the reason why issue will also provide the answer to the less favourable treatment issue.”

and:

“Was [the offending treatment] on the proscribed ground which is the foundation of the application? This will call for an examination of all the facts of the case. Or was it for some other reason? If the latter, the application fails.” (para [18])

These passages reinforce that tribunals must not artificially separate “whether there was less favourable treatment” from “why the treatment occurred.” The two questions are “intertwined.” The Court of Appeal then evaluated the Tribunal decision against this standard and found that the “why” analysis was effectively absent.

3.2 Lord Rodger in Shamoon and Nagarajan v London Regional Transport

The Court also relied upon Lord Rodger’s observations in Shamoon, itself drawing on Nagarajan v London Regional Transport [2000] 1 AC 501 (para [19]).

Lord Rodger recognised that discrimination:

“is rarely open and may not even be conscious … [and] will usually be proved only as a matter of inference.”

But he added a crucial qualification:

“Of course, a tribunal cannot draw inferences from thin air, but it can draw them by using its good sense to evaluate the evidence, including the comparisons offered.”

This passage underpins the Court’s criticism that the Tribunal here drew an inference of sex discrimination without an adequate evidential base or clear reasoning – essentially, “from thin air”.

Lord Rodger further stressed that in assessing comparators:

“the similarities or differences in the two contexts are precisely what matters…” (para [19], referencing [129] in Shamoon)

That point directly underpins the Court’s finding that the Tribunal acted irrationally in both:

accepting that the claimant’s female comparators were in materially different circumstances, yet
treating them as if they were valid statutory comparators in its analysis.

Finally, relying on Nagarajan, Lord Rodger underscored the centrality of the alleged discriminator’s mental processes in answering the “why” question – what was actually in the mind of the decision‑maker.

3.3 Nesbitt v The Pallet Centre [2019] NICA 67

The court referred to its own earlier decision in Nesbitt v The Pallet Centre [2019] NICA 67 (para [20]) as setting out the proper function of the Court of Appeal in employment discrimination appeals. The key propositions (referred to, albeit not fully set out) are:

Appeals lie only on points of law, not on pure findings of fact.
An “error of law” includes:
- misdirection or failure to apply the correct legal test,
- failure to take into account relevant evidence or taking into account irrelevant matters,
- factual findings that are perverse (no reasonable tribunal could have reached them), and
- inadequate or incoherent reasoning that prevents the appellate court from understanding how legal conclusions were reached.

Measured by these standards, the Court held that the Tribunal’s decision in O’Neill contained multiple material errors of law.

3.4 Sex Discrimination (Northern Ireland) Order 1976

The decision centres around Articles 3 and 63A of the SDO 1976:

Article 3 defines discrimination on the grounds of sex, mostly by reference to less favourable treatment of one sex compared with another “in the same or not materially different circumstances”.
Article 63A embodies the EU‑driven reverse burden of proof: once the claimant proves facts from which the tribunal could conclude that discrimination occurred, the burden shifts to the employer to prove that the treatment was in no sense on the proscribed ground (here, sex).

The Court’s main task was to decide whether the Tribunal had lawfully found that Mr O’Neill had established such a prima facie case, and if so, whether it lawfully assessed the Council’s explanations under Article 63A.

4. Legal Reasoning and Critique of the Tribunal

4.1 Structural defects in the Tribunal’s reasons

The Court’s first criticism was methodological: the Tribunal’s “Findings of Fact” section was not a true set of findings. Instead, it largely repeated narrative and evidence, without:

making clear, specific, numbered findings of fact, and
linking those findings to each of the nine allegations of discriminatory treatment (para [21](i)).

This is not a mere stylistic objection. In discrimination cases, the issues are often multi‑layered and fact‑sensitive. The Tribunal had listed nine separate particulars, but the Court observed that:

some were never addressed by any clear factual finding, and
for others, the reader is left to perform a “forensic exercise” to glean what might have been concluded.

This lack of structure made it impossible to see how the Tribunal had moved from evidence to findings, from findings to inferences, and from inferences to legal conclusions on discrimination. Under Nesbitt, that opacity constitutes an error of law.

4.2 Unparticularised criticism of the Council’s evidence

At para [13](i), the Tribunal characterised the Council’s evidence as “incohesive, confusing and difficult to collate,” requiring “multiple clarifications.” The Court described this as “crying out for specificity” (para [21](ii)).

Why is that important? Because such a negative global assessment of a party’s evidence can materially influence:

whether the tribunal accepts that party’s non‑discriminatory explanations, and
whether it is prepared to draw adverse inferences of discrimination.

Yet the Tribunal had not:

identified which witnesses were incoherent,
explained which aspects of evidence were contradictory or confusing, or
made concrete findings that particular explanations were factually untrue or unreliable.

Absent such specificity, an appellate court cannot meaningfully review whether it was lawful for the Tribunal to reject the Council’s explanations and to conclude that the burden of proof had not been discharged. The Court therefore treated this as a further inadequacy of reasons.

4.3 The hypothetical comparator: a conclusion without content

The Tribunal found that a hypothetical female comparator would have been “more favourably treated than the claimant” (para [13](ii)). The Court described this as another “purely conclusionary statement” (para [21](iii)), asking, in effect:

In what respect would a hypothetical female have been treated more favourably?
At which decision‑points (non‑renewal, redeployment, matching, creation of posts)?
By whom and based on which features of the evidence?

While tribunals are allowed – and indeed often required – to use hypothetical comparators in sex discrimination cases (especially where no precise real‑life comparator exists), a hypothetical comparator must be:

clearly defined (what are that person’s role, circumstances, contractual position?), and
linked to specific findings about likely treatment.

Here, although Ms Maguire had argued that the hypothetical comparator was “a female who is in a seconded post in one department and whose substantive post in another department is subject to funding” (para [16]), the Tribunal’s reasons did not articulate how this definition translated into a concrete, fact‑based conclusion that such a woman would actually have been matched, assimilated or made permanent where Mr O’Neill was not.

In the Court’s view, this omission fatally undermined the lawfulness of invoking a hypothetical comparator as the core foundation for a finding of discrimination.

4.4 Absence of findings on the discriminatory decision and decision‑maker

The Court was particularly critical that the Tribunal failed to identify:

what exactly the discriminatory act or decision was (e.g. non‑extension of the CPM contract in June 2022? refusal to make him permanent in 2019? allocation of his duties to LO?);
who the relevant decision‑maker(s) were; and
why (by reference to sex) they acted as they did (para [21](iv)).

This is the “reason why” issue emphasised in Shamoon and Nagarajan. A tribunal cannot simply identify that A’s outcome was worse than B’s and move directly to a finding of discrimination. It must:

determine that A was treated less favourably than an appropriate comparator (real or hypothetical); and
ask whether that less favourable treatment was on grounds of sex, or for some other, non‑prohibited reason.

In this case, the Tribunal’s reasoning blurred those steps, and it never specifically articulated the mental discrimination – conscious or unconscious – it attributed to the Council.

4.5 Misuse of non‑qualifying comparators

The Tribunal correctly found that Mr O’Neill’s chosen female comparators were not in the “same or not materially different circumstances” as required for statutory comparison (para [13](ii)). For example:

LO’s department was dissolved, giving rise to a redundancy‑type situation and suitable alternative employment considerations (para [12](e), (f));
MM and EO’s original posts were extinguished, and they were assimilated into new posts similar to their former roles (12(d));
Mr O’Neill’s own substantive department (CRM role) remained, so he could revert to it without redundancy.

Despite that, the Tribunal then:

treated their progression into new posts as direct comparators, and
used the pattern of their more favourable treatment as if it were evidence satisfying the Article 3/Article 7 comparator requirement (para [13](iii)).

The Court found this “plainly unsustainable” (para [21](v)). This does not mean that tribunals can never look at how dissimilar colleagues were treated. As Lord Rodger said (para [19]), tribunals may use “comparisons offered” as part of the evidential picture. But they must:

recognise when a person is not a proper statutory comparator, and
avoid treating non‑qualifying comparators as if they satisfied the statutory test of “same or not materially different circumstances.”

Here, the Tribunal effectively contradicted itself: it said the comparators were not materially similar but nonetheless proceeded as though they were appropriate comparators, using their treatment to underpin its discrimination finding.

4.6 Failure to engage with obvious non‑discriminatory explanations

The Court identified two clear non‑discriminatory explanations advanced by the Council (para [21](vi)):

Mr O’Neill was occupying a genuinely temporary fixed-term post (CPM) pursuant to a contract that eventually expired and was not renewed; and
His role came to an end as part of a broader, legitimate restructuring exercise, in which some posts disappeared, some departments were dissolved, and others (including his substantive CRM post) remained.

The existence of these explanations did not automatically defeat the discrimination claim – a fixed‑term or restructuring process can still be applied in a discriminatory way. But Shamoon requires the Tribunal to squarely ask whether the adverse treatment was on grounds of sex or “for some other reason.” The Tribunal did not do that.

Instead, it focused on the duration of the CPM contract (3.5 years) and the lack of evidence that it could not have been extended to four years so as to make him permanent (para [13](iii)). That reasoning:

might support a complaint about unfair procedures or breach of a local permanency policy, but
does not in itself establish that sex was causative, or even a factor, in the decision not to extend.

Moreover, once the Tribunal had decided that the burden of proof had shifted (because a prima facie case of discrimination had been made out), it was obliged to:

set out the Council’s non‑discriminatory reasons (fixed-term nature, restructuring), and
explain, in detail, why those reasons were rejected as untrue or insufficient.

Because it did not do so, its conclusion that the Council had failed to discharge the burden under Article 63A was legally defective.

4.7 The burden of proof and “prima facie” case

Ground 1 of the appeal (para [14](i)) directly challenged the Tribunal’s conclusion that Mr O’Neill had proved facts which, absent explanation, could lead to a finding of discrimination – the threshold for the burden of proof to shift.

Implicit in the Court of Appeal’s analysis is that:

because the factual findings were incomplete and unstructured, and
because the Tribunal did not properly handle comparators or the employer’s explanations,

it was wrong to invoke Article 63A in the way that it did. The claimant simply had not established a coherent set of facts from which a reasonable tribunal could infer that sex discrimination, rather than fixed‑term structures and restructuring, was the operative cause of his less favourable treatment.

5. Impact and Significance

5.1 For employment tribunals: structuring discrimination judgments

The judgment sends a clear message to tribunals in Northern Ireland (and, by analogy, to courts and tribunals elsewhere applying similar discrimination legislation):

Make discrete, issue‑linked findings of fact. Where a claim is broken into particularised allegations (as here, nine), tribunals should state expressly what they find in relation to each, and why.
Avoid conflating narrative with findings. The fact‑finding section must not simply rehearse evidence; it must identify what the tribunal actually accepts as fact.
Use comparators correctly. Tribunals must be clear when a person is:
- a proper statutory comparator,
- merely background evidence, or
- not relevant at all because their circumstances are too distinct.
Articulate the hypothetical comparator. When relying on a hypothetical comparator, define it precisely and explain concretely how that person would have been treated differently.
Identify the discriminatory decision and decision‑maker. Tribunals must be able to say what the adverse act was, who made it, and why (in terms of proscribed grounds) that person acted as they did.
Engage directly with non‑discriminatory reasons. Especially once the burden of proof has shifted, tribunals must summarise, scrutinise and – where appropriate – reject the employer’s explanations with clear reasons.

While tribunals are often faced with time pressures and complex bundles, O’Neill underlines that in discrimination cases, careful structuring and reasoning are not optional; they are essential to avoid appealable errors of law.

5.2 For claimants: evidential strategy

From a claimant’s perspective, the decision emphasises:

It is not enough simply to point to grievance, dissatisfaction or general unfairness.
There must be:
- a clear theory of which specific decisions were discriminatory,
- who made them,
- why they are linked to the protected characteristic (here, sex), and
- how proper comparators (or a well‑defined hypothetical comparator) would have been treated.
An “overwhelmingly female” workplace does not, on its own, make out a prima facie case of discrimination, though it can form part of the contextual picture.
Where employers advance obvious alternative explanations – e.g. fixed‑term status, restructuring, loss of funding – claimants should gather evidence to undermine or challenge those explanations, not assume they can be swept aside by inference.

5.3 For employers: managing restructurings and fixed‑term roles

For employers, the case highlights both risks and safeguards:

Fixed-term contracts: Employers may legitimately use fixed‑term arrangements, but must:
- document clearly the temporary nature of roles and any funding constraints, and
- apply policies (e.g. concerning permanency after a given period) consistently across genders.
Restructuring exercises: When dissolving departments and redistributing roles:
- retain documentary records showing the objective reasons for matching or assimilating staff to new posts, and
- ensure that redeployment and redundancy decisions do not, even inadvertently, place members of one sex at a systemic disadvantage.
Evidence at tribunal: Vague or inconsistent explanations risk being labelled “incohesive.” Employers should present:
- clear oral and written evidence of decision‑making processes,
- who took which decisions, when and why, and
- how all affected employees (male and female) were treated.

However, the decision is also a reminder that where employers have:

clear fixed‑term contracts, and
genuine, non‑discriminatory restructuring processes,

tribunals should not lightly find discrimination without adequately engaging with those explanations.

5.4 Systemic significance

Armagh City, Banbridge and Craigavon BC v O’Neill does not break new legal ground in the sense of creating a novel test. Its significance lies in its procedural and analytical discipline. It reinforces that:

the Article 63A burden‑shifting mechanism must be used carefully,
comparators (statutory and hypothetical) require precision, and
tribunal reasoning must allow an appellate court to see how the conclusion of discrimination was reached.

Given the frequency of appeals in discrimination cases grounded on inadequate reasoning, this judgment will likely be cited to remind tribunals to structure their decisions in a way that clearly separates:

what happened (facts),
how others in genuinely similar situations were treated (comparators), and
why the difference in treatment occurred (causation and proscribed ground).

6. Complex Concepts Simplified

6.1 Statutory comparator vs hypothetical comparator

A statutory comparator is an actual person of the opposite sex who is or was in the “same or not materially different circumstances.” For example, another Tier 4 manager in a broadly similar contractual position, facing similar organisational changes.
A hypothetical comparator is an imagined person. The tribunal asks:
If the claimant had been a woman (with the same role, history, qualifications and circumstances), would the employer have acted differently?

In either case, the comparator must be carefully defined. The comparison fails if the other person’s circumstances are too different (e.g. their whole department was dissolved, or they lacked a substantive role to return to).

6.2 Burden of proof and “prima facie” case

In discrimination law, the burden of proof works in two stages (reflecting Article 63A SDO 1976):

The claimant’s burden: The claimant must prove facts from which a tribunal could infer discrimination – e.g. less favourable treatment of a man compared with a similarly situated woman, an overwhelmingly gendered pattern of treatment, suspicious timing, or implausible explanations. This is often called establishing a prima facie case.
The employer’s burden: If that threshold is met, the burden shifts to the employer to prove that the treatment was “in no sense whatsoever” on grounds of sex, but was instead wholly for a non‑prohibited reason (e.g. genuine redundancy, funding loss, capability).

If the employer fails to discharge this burden, the tribunal must find discrimination established.

6.3 “Matching” and “assimilation” in restructurings

In organisational restructurings, employers often:

“Match” employees from an old post to a new post with substantially similar duties and grade.
“Assimilate” employees into newly created posts that broadly correspond to their previous functions and seniority.

These processes can be legitimate ways to avoid redundancy but become problematic if, for example, women are routinely matched into secure posts while men’s temporary roles are simply allowed to expire without equivalent opportunities.

6.4 Fixed-term contracts and permanency

A fixed-term contract is an employment contract that ends automatically at a specified date or on completion of a project/funding stream. In many legal systems and local policies:

employees on repeated or long‑running fixed‑term contracts may have rights to permanency after a certain period (e.g. four years, or as per a collective agreement or circular);
however, those rights are conceptually distinct from discrimination rights: failure to make someone permanent may be unfair or unlawful for other reasons but is only discriminatory if the reason is (even in part) their sex (or another protected characteristic).

6.5 Error of law vs error of fact

An error of fact occurs when a tribunal makes a mistaken finding about what actually happened (for example, misremembering a date). Appeal courts rarely interfere unless no reasonable tribunal could have made that finding (perversity).
An error of law includes:
- applying the wrong legal test,
- failing to consider relevant evidence,
- taking into account irrelevant considerations, or
- giving such inadequate reasons that the legal route to the conclusion is opaque.
O’Neill falls in the last category: the Court could not see how the Tribunal had lawfully moved from evidence to a conclusion of sex discrimination.

7. Conclusion

Armagh City, Banbridge and Craigavon Borough Council v O’Neill [2025] NICA 61 is a careful reminder that discrimination law is as much about process and reasoning as it is about substantive fairness. The Court of Appeal did not pronounce that Mr O’Neill was not discriminated against; instead, it held that the Tribunal had not reasoned its way to that conclusion in a legally sustainable manner.

The decision sharpens several key points:

Tribunals must give structured, issue‑focused findings of fact, clearly related to the pleaded allegations.
Less favourable treatment and causation (“why?”) must be analysed together, not in isolation.
Comparators – real or hypothetical – must be carefully defined, and non‑qualifying comparators cannot be treated as though they satisfy statutory requirements.
Obvious non‑discriminatory explanations such as fixed‑term status and restructuring must be explicitly addressed, especially once the burden of proof has shifted.

On remission, a differently constituted Tribunal will have to reconsider the evidence afresh and apply these principles rigorously. Whatever the eventual outcome for Mr O’Neill, this appellate decision will stand as a guide for future discrimination cases in Northern Ireland, reinforcing the importance of coherent reasoning, disciplined use of comparators, and proper operation of the statutory burden‑shifting regime.

Coherent Reasons, Comparators and Burden of Proof in Sex Discrimination Cases: Commentary on Armagh City, Banbridge and Craigavon Borough Council v O'Neill [2025] NICA 61