Understanding AI in Litigation: Re Walker [2025] VSC 714 Responsibilities and Risks

In May 2024, the Victorian Supreme Court issued guidelines on the responsible use of artificial intelligence in litigation. These guidelines outline several key principles governing litigants and practitioners use of AI tools.

First, anyone using AI in litigation must understand how these tools work. They must also be aware of their limitations. This understanding helps legal practitioners feel competent and assured in their use.

Secondly, AI-generated material must not mislead other parties or the Court about its actual production. As a general rule, parties should disclose any AI assistance used in preparing their material.

Thirdly, any use of AI remains subject to ordinary professional duties. This includes the duty of candour and compliance with the Civil Procedure Act 2010.

The guidelines also explain how these principles apply in practice. Generative AI tools, like ChatGPT or Google Gemini, do not reason. They are not legal research platforms. Instead, they generate text by predicting probable word sequences. Their output depends heavily on the data provided. It is not inherently reliable. It is more likely to be inaccurate in the context of live litigation.

Signing a court document signifies it has been checked. It is accurate. This underscores the importance of strict adherence to formalities. Such adherence reassures legal professionals of procedural reliability.

The mere fact that the preparation of a document with generative AI assistance does not excuse errors or omissions. Elliott J emphasised a crucial point in Director of Public Prosecutions v GR [2025] VSC 490. Strict adherence to these guidelines is essential. Courts rely on the accuracy of submissions to administer justice effectively.

Unsupervised or careless use of AI risks undermining court processes. It can also delay justice. Thorough verification of AI-produced texts is essential to maintain trust in legal proceedings.

The law presumes that a testator knew the contents once they duly execute a Will with testamentary capacity. It also presumes the testator approved the contents. However, recent guidelines on AI use in litigation highlight the importance of verifying AI-assisted assessments of testamentary capacity. This is especially crucial when suspicious circumstances arise. If such circumstances exist, the burden shifts back to the propounder to affirmatively prove knowledge and approval.

A mere allegation of concern is not enough. The person challenging the Will must establish facts. These facts must give rise to a well-grounded judicial suspicion. They should show that the Will does not truly reflect the testator’s intentions. Only then does the propounder have to dispel that suspicion.

The classic principles from Bailey v Bailey 34 CLR 558 [1924] HCA 21 confirm that:

• The propounder bears the overall burden of proving that the document is the testator’s Will. That burden remains throughout the case and must be assessed based on all the evidence.

• The propounder discharges the initial burden by establishing a prima facie case of due execution and capacity. The onus intensifies only if suspicious circumstances arise.

• The level of proof required from the propounder to dispel suspicion depends on the nature of those circumstances.

Courts are particularly vigilant in situations where someone who benefits under the Will has played a role in preparing it. They are equally vigilant if someone has arranged its execution. Barry v Butlin(1838) 2 Moo PC 480 demonstrates the broad principle. Wintle v Nye[1959] 1 WLR 284 (HL) at 291 also illustrates it. Furthermore, Fulton v Andrew (1875) LR 7 HL 448, 472 showcases it. Any circumstance that reasonably arouses suspicion—whatever its form—requires the propounder to rebut it with convincing evidence.

Suspicion may arise from:

• a beneficiary’s involvement in drafting or organising the Will;
• significant and unexplained changes from longstanding testamentary intentions;
• influence or dependency, especially in cases involving carers or dominant personalities;
• the testator’s physical frailty or cognitive vulnerability;
• abrupt departures from previous Wills favouring someone exercising power over the deceased.

However, there is a connection of suspicion to the preparation, contents, or execution of the Will itself. Events occurring after the testator’s death will rarely provide insight. They seldom indicate whether the testator knew and approved the document during life.

As emphasised in McKinnon v Voigt[1998] 3 VR 543, the suspicion must be more than a bare assertion. It must be a rational, judicially sound concern. This concern should be grounded in the evidence.

Cheryl Green (the plaintiff) applies for probate of a Will dated 27 May 2020. The Will was made by her sister, Sharon Louise Walker (the deceased). Sharon died in April 2023 at the age of 57 from endometrial cancer. The value of the estate is about $952,000 (after a small mortgage). The only substantial asset is a residential unit in Vermont that the deceased developed some years earlier. The deceased lived there with her husband, Kyriacos Toumazou, from 2017, and they married later that year.

The 2020 Will

The Will granted the husband a rent-free right to live in the property for life. This right continues until he leaves or requires full-time care. After that, the executors are to sell the property. The proceeds are to be divided equally between the plaintiff and the deceased’s other two sisters. The husband opposes probate. He alleges the execution of the Will did not comply with s 7 of the Wills Act 1997 (Vic). The plaintiff accepts that formal execution is in issue. If needed, the Court should admit the document as an informal Will under s 9. The defendant withdrew an earlier attempt to have the plaintiff “passed over” as executor. However, the Court ultimately revisits this point.

The plaintiff and her sisters gave evidence. Three longstanding friends of the deceased also contributed. A solicitor from Rose Lawyers, who drafted the Will, provided testimony as well. The Court accepted them all as reliable witnesses. Their evidence provided a coherent picture of the deceased’s circumstances, illness, marriage, and testamentary intentions. The defendant called only a former law clerk and himself. The clerk was credible. However, the Court rejected the defendant’s evidence for reasons set out later in the judgment.

The Will comprises four typed pages from Rose Lawyers. It appears to bear the signatures of the deceased and two witnesses. The witnesses are Sebastian Hong and Madeleine Cook. Their signatures are beneath a standard attestation clause. However, Ms Cook’s signature is missing from the bottom of page 2.

Clause 8 governs the property. It grants the defendant the right to reside rent-free and requires the estate to maintain the property. Then, it directs the executors to sell the property upon termination of the husband’s occupation. The proceeds are to be distributed among the deceased’s three sisters, with a substitutional gift for their adult children.

Clause 9(b) distributes the residuary estate. It allocates 50% to the defendant and 10% to Benwerren. It gives 20% to the sisters. Additionally, 10% goes to the nieces and nephews, and 10% to the deceased’s father. At death, her three sisters and seven nieces and nephews survived the deceased.

The defendant relied on several matters said to raise such suspicions. Before assessing those arguments, the Court turned to the factual findings about how the deceased’s Will was prepared. The execution of the Will also came under scrutiny. These findings broadly aligned with the plaintiff’s submissions and were supported by the documentary record.

The Propounder’s Burden and Presumptions

Santamaria JA explained in Veall v Veall[2015] VSCA 60; 46 VR 123. The person seeking to prove a Will must prove two things.

Firstly, the testator had testamentary capacity.

Secondly, the testator knew and approved the contents of the Will.

Meeting the formal execution requirements in the Wills Act is central to satisfying this burden.

1. Where the document appears rational and properly executed, the presumption is that the testator had capacity.Extra proof of capacity and due execution supports the presumption that the testator knew and approved the Will.

2. Statutory Formalities

Section 7(1) of the Wills Act sets out four mandatory elements for a valid Will. It must be in writing. It must be signed by the testator or someone at the testator’s direction. There must be the testator’s intention that the signature executed the Will. It must be signed or acknowledged in the presence of two witnesses. Those witnesses must attest and sign in the testator’s presence.

3. Presumption of Regularity

If a Will appears on its face to comply with s 7(1), the Court presumes that it meets the formalities. This presumption holds unless clear evidence shows otherwise. The general presumption that official acts are properly performed (omnia praesumuntur rite esse acta). An attestation clause is prima facie evidence that the will maker executed the Will correctly.

4. Was there Due Execution of the Will

The Will here was in writing. It bore the signatures of the deceased and two witnesses under a standard attestation clause. It therefore attracted the presumption of due execution, despite the absence of a witness’s signature on an internal page.

The real issue arose from the defendant’s claim that one witness, Ms Cook, was not present when the deceased signed. Both witnesses recognised their signatures but had no memory of this specific will-signing. The Court emphasised longstanding authority requiring strong or compelling evidence to displace the presumption created by a complete attestation clause.

5. Assessment of the Defendant’s Evidence

The defendant’s oral evidence was the only basis for alleging Ms Cook was absent. The judge found him an extremely unreliable witness. He was evasive and argumentative. He was self-serving and unwilling to make apparent concessions. He was also prone to hostility toward other parties. His testimony was riddled with implausible assertions and contradicted by documentary evidence. The Court concluded his broader credibility problems fatally undermined his account. This was the case even though he was assisted by an interpreter.

The defendant’s evidence lacked reliability. It fell far short of the “compelling” standard needed to rebut the presumption of due execution. As a result, the challenge failed.

6. Independent Basis for Finding Due Execution

Even aside from the presumption, the Court was independently satisfied that Ms Cook was present. One witness, Mr Hong, had sworn an affidavit two years earlier. He stated that he and Ms Cook witnessed the testator sign each page. Although he no longer recalled the event at trial, his affidavit recorded a specific memory at the time. His credit was unchallenged. The Court accepted that evidence.

Was the Will Duly Executed?

The Will appeared to be formally valid. It was in writing and bore the signatures of the deceased and two witnesses. The standard attestation clause stated that they all signed in each other’s presence. This facial compliance engages the presumption of due execution. Although one witness, Ms Cook, had not signed one internal page, this did not affect the Will’s formal validity.

The plaintiff nonetheless accepted that there was a genuine factual issue. The issue was whether both witnesses were actually present when the deceased signed. This was due to the defendant’s claim that Ms Cook was not. Both witnesses identified their signatures and described their general practice, but had no specific recollection of this signing.

The authorities emphasise that courts require strong evidence. The evidence must be compelling. It must be so before accepting that the testator did not properly execute a Will with a regular attestation clause. A mere suggestion or uncertain proof is insufficient to rebut the presumption; only convincing evidence can do so.

Here, the defendant was the only person asserting Ms Cook’s absence. His credibility, however, was profoundly compromised. His evidence was evasive, argumentative, internally inconsistent, and frequently implausible. He made unfounded allegations, refused reasonable concessions even in the face of clear documents, and adopted self-serving interpretations of evidence.

The defendant’s behaviour in the witness box was remarkable. He turned to the public gallery to make provocative comments. This reinforced the judge’s conclusion. The judge decided that he was an unreliable and partisan witness. His evidence could not be safely accepted on any contested issue unless corroborated. Even allowing for the difficulties of giving evidence through an interpreter, the judge found the defendant’s credibility fundamentally defective. His testimony could not rebut the strong presumption of due execution.

As a result, there was no satisfactory—let alone compelling—evidence that Ms Cook was absent when the testator signed the Will. The presumption of due execution remained intact.

In any event, the Court was independently satisfied that the testator properly witnessed the Will. In July 2023, Mr Hong swore an affidavit. The other witness stated that he specifically recalled both himself and Ms Cook. They witnessed the deceased sign each page of the Will. His credit was unchallenged, and the plaintiff did not cross-examine Mr Hong on this point. The Court accepted this evidence as reliable.

Moore J concluded that the testator duly executed the Will in accordance with the statutory formalities.

In January 2020, the deceased and the defendant met with Rose Lawyers to prepare wills. The deceased instructed that:

• her sister (the plaintiff) would be the executor;
• her husband would receive a life interest in the Vermont property; and
• after the life interest ended, the executor would sell the property. The proceeds would be shared equally among her three sisters.
• finalisation of the deceased’s instructions for the rest of her estate was to occur later.

The deceased’s solicitor provided a draft Will in March 2020. It appointed the plaintiff as executor. It created a life interest in the property for the defendant, with the estate funding outgoings and care costs. The remainder was left to the sisters.

In April 2020, the deceased texted the plaintiff expressing concern about the draft’s complexity. She did not understand the powers included, especially those given to the substitute executor. She emailed the solicitor seeking clarification. The deceased noted she thought the property would go directly to the sisters. It was subject to the husband’s life interest. She provided clear instructions for distributing her non-property assets. These included specific percentages to the defendant, family members, and a charity.

Further messages in late May 2020 show the deceased continuing to refine her planning. She checked whether superannuation would fall into her estate. On the morning of 27 May 2020, the deceased’s solicitor advised that she had updated the Will. The deceased was informed to attend the office at 4 pm to sign it. The deceased told a friend earlier that day that she was going to sign the Will.

From these communications, the Court inferred that the deceased’s questions prompted amendments. These changes are reflected in the differences between the draft and final Will.

Assessment of Alleged Suspicious Circumstances

The defendant argued that various factors created suspicious circumstances, casting doubt on the deceased’s knowledge and approval of the Will. The Court rejected each of these arguments:

The suggestion that the deceased signed the Will without both witnesses present was dismissed. It was inconsistent with earlier factual findings.

Alleged missing “updated” draft.

An email suggested that the solicitor prepare another draft, which was not located, and this did not raise suspicion. If anything, it reflected further review and consideration.

Claim that the deceased was distressed or distracted before surgery.

The defendant argued the deceased was confused on 27 May 2020 due to a major operation scheduled the next day. The Court found no evidence that the surgery was life-threatening, and the supporting evidence was misconstrued. The defendant’s own testimony was vague and unreliable. Contemporaneous messages from the deceased showed no distress or confusion. Even if she was anxious about surgery, that did not indicate she did not understand her Will.

Differences between the draft and final Will.

The Court held that revisions from a draft to a final Will are normal. Without more, these revisions do not suggest suspicious circumstances.

There was no superannuation direction in the Will. The defendant argued this showed the deceased misunderstood how the estate would deal with the superannuation. The Court found the opposite.

Evidence from friends indicated the deceased intended her superannuation to fall into her residuary estate. This would have occurred but for the defendant’s actions in requesting that the funds be paid directly to him.

Lack of assets to fund the upkeep of the property. The Court found the deceased intended her superannuation to provide this fund. The shortfall happened because the defendant successfully claimed the superannuation. This was not due to any misunderstanding on the deceased’s part.

The defendant’s provision is allegedly inadequate or “strange.” The defendant said the Will was suspicious because as a spouse it gave him only a non-portable life interest. Moore J noted the marriage was relatively short and began later in life. There is nothing inherently suspicious in prioritising siblings while still making some provision for a spouse. A “portable” life interest was an estate-planning concept that the deceased’s solicitor may not have provided advice about.

Claims of significant financial contributions by the defendant. The defendant submitted that the deceased’s dispositions were inexplicable, given that he had made substantial financial contributions to her property.

Moore J rejected this. He found the defendants’ evidence inconsistent and unsupported. It was contradicted by loan-repayment records. The witness evidence provided no credible evidence of the claimed contributions.

Conclusion

The Court held that none of the defendant’s arguments, either individually or collectively, established any suspicious circumstances. There were no suspicious circumstances surrounding the making of the Will. The deceased’s testamentary arrangements were rational, consistent, and the product of several months of consultation and clarification with her solicitors. The deceased read the draft, sought explanations, requested changes, and ultimately signed a Will that she understood and approved. The Will reflected the deceased’s genuine testamentary intentions.

Use of artificial intelligence

During the hearing, it became clear that the defendant’s solicitor, Ms Seham Rizkallah, relied on an artificial intelligence tool. She used it to draft part of her client’s opening submissions. This use of AI breached the Court’s published guidance on responsible AI use in litigation. It ultimately led to the inclusion of fabricated—so-called “hallucinated”—citations.

The Court first issued its Guidelines for the Responsible Use of Artificial Intelligence in Litigation in May 2024. The document outlines several key principles governing how lawyers may use AI tools. Among them:

• Understanding and limitations — Lawyers who use AI must understand how the tool operates and appreciate its limitations.
• Avoiding indirect misleading conduct — a party must not use AI to mislead the Court.
• Misleading other parties about the nature of the work or the accuracy of the content is also prohibited. Generally, parties should disclose when using AI assistance.
• Professional responsibilities remain unchanged. Legal work aided by AI is still governed by core professional obligations. These include the duty of candour to the Court and the requirements of the Civil Procedure Act 2010.

The Guidelines also explain how these principles apply in practice. They emphasise that generative AI and large language models are not legal research tools and do not produce reasoning-based output. Instead, they generate text probabilistically. Meaning inaccurate, incomplete, or entirely incorrect results. Including the invention of cases or legal propositions.

Moore J stresses that any practitioner who signs, files, or otherwise relies on a document hold responsibility for it’s accuracy. Practitioners must take full responsibility. This applies regardless of any AI assistance used in preparation. Claiming that errors occurred because a party uses a generative AI tool does not excuse mistakes.

Elliott J’s comments in Director of Public Prosecutions v GR [2025] VSC 490 reinforce this point. Adherence to the Guidelines is essential. Courts depend on the accuracy of submissions to administer justice effectively. Any unverified use of AI risks compromising those processes.

“At the risk of understatement, the manner in which these events have unfolded is unsatisfactory

…

The ability of the court to rely upon the accuracy of submissions made by counsel is fundamental to the due administration of justice. Self-evidently, as was immediately and unequivocally acknowledged by counsel in this case, any use of artificial intelligence without careful and attentive oversight of counsel would seriously undermine the court’s processes and its ability to deliver justice in a timely and cost-effective manner.

Regrettable as it is to single out counsel and their instructing solicitors in this case for what has occurred, in light of the matters set out above it is important to record that counsel must take full and ultimate responsibility for any submissions made to the court. To this end, it is not acceptable for artificial intelligence to be used unless the product of that use is independently and thoroughly verified. The same may be said for solicitors responsible for producing or filing court documents.” Director of Public Prosecutions v GR [2025] VSC 490 at [78]-[80]

The message is clear. Lawyers may not use AI to prepare court documents. They must independently verify every aspect of the AI-generated material.

The Solicitor’s Explanation

In her affidavit, the solicitor explained that she:

1. had limited experience using the AI tool;
2. was unaware of the Court’s AI Guidelines at the time;
3. assumed that any missing cases were paywalled or unreported, rather than fabricated; and
4. accepted responsibility and apologised.

The Solicitor also proposed adopting an internal verification protocol that includes manually checking all authorities before filing.
The Court’s Response:

Professional Standards Still Apply

The Court held that the solicitor’s conduct amounted to unsatisfactory professional conduct. Several factors were significant:

1. Ignorance of the AI Guidelines was not an excuse; practitioners must keep abreast of court requirements.
2. Reliance on unverified AI output is incompatible with the duty of competence and diligence.
3. Signing submissions containing fictitious authorities undermines public confidence in the administration of justice.
4. The increasing prevalence of AI misuse in litigation creates a need for general deterrence.
5. The Court imposed a disciplinary penalty.
6. The Court declined to refer the matter to the Victorian Legal Services Commissioner. Noting that the facts were clear and the incorrectly supported argument was ultimately not pursued at trial.

Why This Matters for Lawyers Using AI
This decision is a wake-up call for the profession. AI is now unavoidable—but professional responsibility is not delegable to a machine.
Key lessons include:

1. AI is not a legal research tool.
   AI can explain principles or generate summaries. However, it cannot be trusted to create accurate case citations. It cannot provide statutory references. Always check primary sources.
2. Verification is non-negotiable
   If an AI tool provides an authority, practitioners must independently verify it.
3. Know the rules
   Courts are increasingly issuing AI practice notes and guidelines. These now form part of the professional competence environment.
4. Disclosure matters
   When AI significantly contributes to court submissions or affidavit material, practitioners should disclose this contribution. This helps avoid misleading the Court.
5. You sign it, you own it
   No matter how a practitioner creates a submission—dictated, cut-and-pasted, or machine-generated—it’s the practitioner’s responsibility.
7. Conclusion
   The Rizkallah incident is not about punishing the use of technology. It is about reinforcing that AI must be used responsibly and transparently. It must always have human supervision. As courts and regulators adapt to the realities of AI-assisted practice, the expectations on lawyers will only become clearer—and stricter.
   Used well, AI can enhance productivity and insight. Used uncritically, it can undermine the very foundations of competent legal practice.

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