AI and family law evidence – An early warning to practitioners and clients  

This article was co-written by Family Law Partner, Katie Stewart, and Family Law Associate Emma Newton. 

A recent Family Court judgement provides a timely warning for anyone tempted to let artificial intelligence (‘AI’) write their evidence for them – polished language and formality is no substitute for an accurate, authentic account in the author’s true voice.  

Family Law solicitors are increasingly receiving documents within proceedings, where it is suspected that they have been drafted with the assistance of an AI tool. Witness statements in particular should be written as the author would speak, in their own voice, respectfully, not one of a robot.  

In the recent judgement, Cornwall Council v M and others [2026] EWFC 306, dated 30 September 2026, HHJ Flexman made care orders concerning three children. An important feature of the case was an independent social worker’s use of Microsoft Copilot to prepare assessment reports, and the judge’s eventual inability to place significant weight on her evidence. 

In the judgement, it was stated that the social worker initially described using AI to improve spelling and grammar. In oral evidence, however, she acknowledged that an entire kinship assessment had been generated from her notes. One part of the social worker’s report even retained AI commentary, with a note that the AI generated wording was more likely to “withstand cross-examination”, exposing the very real need for there to always be human oversight with any AI use. 

The judge distinguished what would be considered lower-risk assistance with transcription to higher risk presentation deemed to be authorship. Generating a whole report had created a significant gap between the expert’s own voice and opinion and the document filed. 

Importantly, this was not a Judge simply stating that the only issues were AI based. There were separate weaknesses in the assessment, and the judge could not establish whether particular errors originated in AI or the social worker’s original notes.  

For those using AI to prepare documents, such as witness statements, the practical lesson is clear. A more persuasive, well-written account is not necessarily a more believable one. Small changes in wording and tone can dramatically alter meaning and validity. The best witness statements tend to be those written based clearly off the client’s true voice, using their tone and language, so it is clear both in written and oral evidence, that this is the same person.  

Our recommendation is that clients discuss any proposed AI use with their solicitor first, disclose any use already made, and check every sentence against their own recollection and any associated documents. Whoever the author, it is essential to remember that a document in proceedings should remain the author’s evidence, not an AI-generated reconstruction. 

The judgement emphasises accountability and transparency, referring to a proposal that experts’ statements of truth should include a declaration that there has been substantive AI use beyond transcription or administration. 

Although this is not currently a requirement imposed on everyone using AI, it is considered that this is a clear warning of the direction of travel. Clients and professionals should be prepared to explain what AI did with any documents produced, what material it processed and how its output was checked. 

AI may assist with the work. It cannot take responsibility for the evidence. All those obtaining legal advice and drafting documents, particularly for court, should be aware of that before, not after, preparing any documents if using an AI tool. 

If you need expert legal advice around family law, you can contact Katie Stewart HERE or Emma Newton HERE.