Drafting affidavits with AI: keep the deponent's evidence their own

By Michael Nadalin, Founder, Market Lead · 19 October 2026 · 7 min read

Picture the third day of a commercial hearing. Your client's general manager is in the witness box, and opposing counsel reads paragraph 14 of his affidavit back to him: "I formed the view that the contractual relationship had irretrievably broken down." Then the question: "Are those your words?" He hesitates, looks at the bench, and says, "Not really. My lawyer wrote that." From that moment the court is weighing his whole affidavit differently.

That problem was around long before generative AI. Solicitors have always been tempted to polish a witness's account into something neater than the witness would ever say. What AI changes is the speed and the scale. A tool can turn a rambling conference note into fluent, confident prose in seconds, and every fluent sentence it adds is one the deponent may not recognise, may not be able to defend, and in some Australian courts may not be allowed to file at all.

This article covers why affidavit evidence has to stay in the deponent's own words, what the NSW Supreme Court now requires, how AI quietly changes evidence, and a practical workflow that lets you use technology where it helps without putting your witness or your practising certificate at risk.

The evidence belongs to the witness, not the drafter

An affidavit is the deponent's evidence in chief, sworn or affirmed. It is not a submission. The court gives it weight because it is supposed to be the witness's own account of what they saw, heard, did and knew. Once the language reads like a solicitor's, or now like a language model's, that assumption weakens, and any experienced judge or cross-examiner can spot the difference.

There is a professional conduct side as well. Rule 24 of the Australian Solicitors' Conduct Rules prohibits advising or suggesting that a witness give false or misleading evidence, and prohibits coaching a witness on what answers to give. The barristers' rules have equivalent provisions. Rewriting a witness's account into stronger or more convenient terms, whether you type it yourself or prompt a tool to do it, comes close to that line, and it does not help that the change happened at the click of a button.

What the NSW Supreme Court now requires

The clearest Australian position is Supreme Court of New South Wales Practice Note SC Gen 23, on the use of generative AI. Among other things, it says generative AI must not be used to generate the content of affidavits, witness statements or character references, and that includes altering, embellishing, strengthening, diluting or rephrasing a witness's evidence. Affidavits and witness statements must include a statement that generative AI was not used to generate their content. Leave to depart from these requirements is available only in exceptional circumstances. Other NSW courts have issued similar guidance.

Courts in other states and the Federal Court have taken different approaches, ranging from guidelines on responsible use to notices asking practitioners for comment. Do not assume that because your matter is outside NSW the issue goes away. The underlying evidentiary and conduct principles apply in every jurisdiction. Before filing anything, check the current practice notes for the specific court and list, because this area keeps changing and the text of each note matters.

How AI changes evidence without anyone noticing

The danger is rarely a single dramatic fabrication. It is drift. Language models are trained to produce fluent, confident, well organised text, and witness recollection is not like that. Real recollection is hedged and out of order, and it is full of 'I think' and 'from memory'. Ask a tool to improve it and the hedges disappear, the sequence becomes neater than events actually were, and inferences turn into statements of fact.

Each version looks reasonable on its own. The problem shows only when you compare the final affidavit with the original conference notes, and by then the witness has read the polished version so often that they may honestly believe it is what they remember. That is the worst outcome. You have not only weakened the affidavit, you have contaminated the witness's memory before cross-examination.

A workflow that keeps the deponent's voice

The safest method is also the oldest: get the witness's account in their own words first, and treat everything else as checking and organising that account. Technology can help at the edges, with transcription, document retrieval and research, but the narrative has to come from the person who will swear to it.

Keep the raw material. A recording or verbatim note of the witness's account, made before any drafting, is your best defence if anyone later suggests the evidence was manufactured. It also lets you check every paragraph of the final affidavit against something the witness actually said.

Fixing AI-assisted drafts already on your file

Many firms will have affidavits in preparation that someone, possibly a junior lawyer or a paralegal working to a deadline, ran through a general AI tool. Do not file them on the hope that nobody will notice. If a disclosure statement is required and it is wrong, the problem is now a statement to the court, not just a style issue.

Work out what happened, go back to the witness's source material, and redraft where needed. Then fix the process so it does not happen again. That usually means a short written policy, a clear rule about which tools may be used on witness material, and supervision that actually checks drafts against notes.

Where AI genuinely helps in affidavit work

None of this means AI has no place in litigation. It is useful for the work around the evidence: finding the authorities on what a party must prove, identifying the facts a witness needs to address, checking procedural requirements for the court you are in, and preparing a properly focused conference. Done well, that makes the conference better, because you know what to ask, and the witness's account stays their own.

The rule of thumb is simple. Use tools to sharpen your questions, never to write the answers. Legal Brain is built for that research side of the work, grounded in Australian law and designed so you can check every source it relies on. The affidavit itself should still sound like the person whose name is at the top of it.

Frequently asked questions

Can I use ChatGPT to draft an affidavit in Australia?

In NSW Supreme Court proceedings, Practice Note SC Gen 23 says generative AI must not be used to generate the content of an affidavit, including rephrasing or strengthening the witness's evidence, unless the court grants leave. Other courts take different approaches, so check the current practice note for your court. In every jurisdiction, the evidence must remain the deponent's own account.

Does an affidavit have to be in the deponent's own words?

It should be. An affidavit is the deponent's evidence, and courts give less weight to evidence that reads like a lawyer's construction. A witness who cannot explain their own phrasing in cross-examination risks damaging their credibility across the whole affidavit.

What is Practice Note SC Gen 23?

It is the NSW Supreme Court practice note on the use of generative artificial intelligence. It covers practitioners' and litigants' use of AI, including restrictions on using it for affidavits, witness statements, character references and expert reports. Read the current version on the court's website before relying on any summary.

Is it coaching a witness to rewrite their affidavit for them?

It can be, depending on what is changed. The conduct rules prohibit suggesting a witness give false or misleading evidence and prohibit coaching them on what answers to give. Removing irrelevant or inadmissible material is legitimate, but changing the substance or strength of what the witness recalls is not.