AI is increasingly finding its way into employment litigation, but recent Northern Ireland tribunal decisions stress that its value, and its risks, lie in how it is applied.

In employment tribunal cases, witnesses usually provide a written witness statement instead of giving evidence orally. Each witness adopts their statement as their evidence to the tribunal before being cross-examined on its contents. The witness statement includes a declaration that its contents are true to the best of the witness’ knowledge and belief.

Two recent cases in Northern Ireland’s industrial tribunals have considered the benefits and drawbacks of using generative AI to help prepare witness statements.

Case one: acceptable use?

In Humphrey v Martin t/a Vitality Skin Clinic (54167/24) the respondent was self-represented. During cross-examination, they admitted to using AI to help with “setting out” their evidence. The claimant’s counsel suggested that the tribunal should give less weight to their evidence as a result, on the grounds that their witness statement was not “her words”.

The tribunal noted that the respondent had adopted the content of their witness statement, and that no specific concerns had been raised about the contents or sources of parts of the statement. The tribunal concluded that the respondent’s AI use to set out their statement “did not adversely affect our view of her evidence.”

Case two: unacceptable use?

However, in Hegarty v NI Fire & Rescue Service (6207/25), the tribunal criticised the “difficulty” caused by a self-represented claimant’s use of AI to prepare their witness statement.

During the case-management process, the claimant had received clear directions that their statement should only contain their factual evidence on the issues in the case. Despite this, the claimant’s statement was “scant” on factual evidence, and instead was a “confusing meld of fact, opinion and legal argument”. This resulted in the claimant providing additional evidence during cross-examination which had not been included in their statement.

Overall, the tribunal concluded that the claimant’s AI use had “immediately cast a shadow over the validity of and weight to the witness statement” and that its use generally was “disturbing” given the statement had been adopted as the claimant’s own sworn testimony. However, the tribunal did not feel required to comment further, as they had found the claimant’s evidence unreliable throughout.

Finding a consensus

These decisions, delivered within weeks of each other, show the potential for tribunals to reach different conclusions based on how AI has been used by individual witnesses.

In Humphrey, the tribunal acknowledged that AI can be used legitimately and, if there is no reason to suggest otherwise, a witness can adopt AI generated statements as their own sworn evidence. In Hegarty, the claimant drew criticism for using AI to generate a statement which was not fit for its intended purpose, making it less helpful for the tribunal.

Both cases can be read consistently with the employment tribunal’s findings in Warrener-Iglesias v Coretech Security Services Limited. In this case, the ET concluded that “the relevance of the Claimant’s use of AI depends on what exactly it has been used for, and what it has produced.”

The ET then distinguished the two ways in which the claimant had used AI: “The parts of the Claimant’s statement that are most obviously GPT-generated are mainly platitudes or bare assertions… That type of evidence is not particularly helpful or persuasive in any event, but I accept that the fact it is not even the Claimant’s own words means that it should be given still less weight.”

As for the evidence in the statement about the Claimant’s life, influences and activities, this would appear to be the Claimant’s own material and thoughts, albeit put into more formal language… He may also have been prompted to include some material he would not otherwise have done because ChatGPT knows what boxes need to be ticked… In my view the Claimant should not be penalised for having used the tool for that purpose. In terms of prompting for evidence… that is very similar to what a solicitor would do when taking a client’s instructions.”

The Civil Justice Council is currently consulting on AI use in preparing court documents, including witness statements, with consultation closing on 14 April 2026.

Its interim report refers to the current AI guidance in the “White Book”, which covers the civil procedure rules in England and Wales, and states that “strong emphasis is placed in the rules on the evidence of the witness being as much as possible in their own words and coming from their personal knowledge. This generally appears to preclude any use of generative AI in drafting them”.

The consultation proposes that witness statements used at hearings should contain a declaration that AI has not been used to generate its actual content, including through altering, embellishing, strengthening, diluting or rephrasing it. This would somewhat conflict with the positions taken by the NI and GB tribunals in the Humphrey and Warrener-Iglesias cases. As always, any resulting practice directions for the employment tfribunals in GB would not be binding in NI, though they would be persuasive in the absence of NI specific guidance.

Effective evidence

It is worth remembering that the purpose of the witness statement is to assist the tribunal, which will determine the case based on the best evidence available to it.

With this in mind, witnesses should ensure that their statements are complete, accurate and effectively convey their position on the relevant issues. The best witness statements will clearly express their personal rationale for any decisions they made. There is no requirement to adopt formal language, and AI could dilute the immediacy or impact of this evidence, especially in the most sensitive cases.

In the cautionary words of the ET in Whelan v Gensight Ltd:

“Rather than using AI, the claimant may well have been much better served by just setting out, in his own words, what it was he wanted to say to the Tribunal in particular, focusing upon the allegations he was pursuing.”

Ultimately, these cases underline that while AI may assist with structure or prompting, the credibility and weight of a witness statement will depend on it constituting the witness’s own clear, factual and personal evidence.

 

For legal guidance and advice regarding AI Policies or Employment Law queries, please contact Jack Balmer or another member of our Employment Team for more information.

While great care has been taken in the preparation of the content of this article, it does not purport to be a comprehensive statement of the relevant law and full professional advice should be taken before any action is taken in reliance on any item covered.