An Analysis of Bailey and Petersen [2026] FCWA 50
1. Introduction
All names used in this article are pseudonyms assigned by the Court. The judgment was published under those pseudonyms with the approval of the Family Court of Western Australia pursuant to s 114Q(2) of the Family Law Act 1975 (Cth). No details in this article identify or are intended to identify any party, witness, or associated person.
Bailey and Petersen [2026] FCWA 50 is a judgment of O’Brien J in the Family Court of Western Australia, delivered on 16 March 2026, that warrants close attention from all legal practitioners—not merely family lawyers. While the decision arose in the context of a parenting dispute under the Family Law Act 1975 (Cth), its analysis of the professional obligations of lawyers in relation to the evidence they place before a court has application across all areas of legal practice.
The judgment addresses a question that arises with regularity in contested proceedings: what is a lawyer to do when a client insists upon filing evidence that is irrelevant, lacking in probative value, or gratuitous? O’Brien J’s answer is unequivocal. The lawyer must exercise independent forensic judgment. That duty is not merely aspirational; it is mandatory. It cannot be displaced by client instructions, client preferences, or client-drafted affidavits. A lawyer who files irrelevant material has failed in a professional obligation.
The significance of the decision lies in its clarity. It consolidates, in accessible terms, the interplay between the overarching purpose provisions of the Family Law Act, the specific powers of the Court in child-related proceedings, and the professional conduct obligations imposed on solicitors and barristers. It does so by reference to a concrete and, as the Court acknowledged, “stark” example (at [94]).
2. Relevant Legal Framework
2.1 The overarching purpose provisions
Section 95 of the Family Law Act 1975 (Cth) sets out the overarching purpose of practice and procedure provisions. That purpose is to facilitate the just resolution of disputes in a manner that, among other things, ensures the safety of families and children, promotes the best interests of the child, and achieves resolution “as quickly, inexpensively and efficiently as possible” (s 95(1)(d)). Section 95(2)(e) requires the disposal of proceedings “at a cost that is proportionate to the importance and complexity of the matters in dispute.”
Section 96 imposes a duty on parties to conduct proceedings consistently with that overarching purpose. Lawyers have a corresponding duty to assist their client to comply with it. As O’Brien J observed at [17], these are duties imposed by statute, not mere aspirations.
2.2 The Court’s powers in child-related proceedings
Section 102NE provides that the Court must actively direct, control and manage the conduct of child-related proceedings. Section 102NN confers broad powers to give directions or make orders about, among other things, the matters on which parties may present evidence, who may give evidence, and the number of witnesses (s 102NN(2)(j)). The Court may also limit or disallow cross-examination of a particular witness (s 102NN(2)(i)).
2.3 The professional conduct obligations
The duties of lawyers as officers of the court are reinforced by the Legal Profession Uniform Law Australian Solicitors’ Conduct Rules 2015 (WA), r 17, and the Legal Profession Uniform Conduct (Barrister) Rules 2015 (WA), rr 42–43. O’Brien J summarised the effect at [23]: lawyers must not act as the “mere mouthpiece” of their client. They are required to exercise independent forensic judgment and do not breach their duty to the client by doing so, even where it means acting contrary to instructions.
2.4 Relevance, admissibility and probative value
Rule 239 of the Family Court Rules 2021 (WA) reflects the fundamental principle that evidence at trial should be limited to facts that are relevant, admissible, and of probative value (at [9]). O’Brien J emphasised that the relaxed evidentiary regime in parenting proceedings—section 102NL permits opinion and hearsay evidence—does not equate admissibility with relevance or probative value (at [12]). The distinction between the unqualified opinion of a lay witness and expert opinion evidence, as discussed in Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705 at 743–744 [85], remains critical.
3. The Facts of the Case
The proceedings concerned parenting arrangements for two children, Charlie (born 2017) and Henry (born 2019), following the separation of Mr Bailey and Ms Petersen. The proceedings were commenced in May 2020 and listed for a seven-day trial before O’Brien J in 2026. Both parties were legally represented. Between them, they proposed to call 25 witnesses (at [1]).
At a Status Hearing in early 2026, the Court confirmed the matters actually in issue. Both parties agreed, through their respective counsel, on a series of concessions that materially narrowed the dispute. These included that there was no risk of the children being exposed to family violence, abuse or neglect in the care of either parent (at [3](a)); that each parent was competent and attentive (at [3](c)); and that both were devoted and engaged parents (at [4](b)). The only identified risk to the children was exposure to the negativity of each parent about the other (at [4](a)).
Against that narrow factual matrix, O’Brien J expressed surprise at both the proposed trial length and the number of lay witnesses: seven for the wife and ten for the husband (at [5]). The Court required counsel to be prepared to make submissions at trial as to why each affidavit, other than those of the parties themselves, the Single Expert Witness, and the family therapist, should be received into evidence (at [6]).
3.1 The husband’s proposed evidence
The husband proposed to rely on evidence from 13 witnesses in addition to his own three affidavits. The Court’s treatment of each is instructive.
Of the 13, counsel for the husband conceded that the evidence of five witnesses—Mr Morgan (at [39]), Mr Becker (at [41]), Ms Orson (at [52]), Mr Leroy (at [54]), Mr Whit (at [56]), and Ms Douglas (at [64])—had no probative value. The concession that Ms Frances Bailey’s evidence similarly lacked probative value followed (at [58]). A subpoena for Dr Johnson was discharged before trial (at [32]).
Three further affidavits were excluded after contested submissions. The affidavit of Ms Radu, a clinical psychologist who had seen the parties years before the children were born, was excluded on the basis that the matters it addressed—an admitted slap and admitted communication difficulties—were already established (at [37]). The affidavits of Mr Robert Bailey and Ms Eliot, siblings of the husband who had limited contact with the children, were excluded for having little relevance and no probative value (at [46], [50]).
Only two affidavits beyond the husband’s own were admitted: that of Ms Michelle Bailey, his mother, who had lived with him and had significant contact with the children, and whose evidence was relevant to an issue raised in the Single Expert Witness’s report (at [60]–[62]); and that of Mr Visser, the husband’s treating psychologist, given the currency of his professional engagement (at [69]).
3.2 The wife’s proposed evidence
The wife proposed seven lay and professional witnesses in addition to her own affidavits. Five lay witness affidavits—from a high school friend, a brother-in-law, a neighbour, a mothers’ group friend, and a retired professional—were sensibly abandoned at trial (at [73]).
The affidavit of Mr Joshua Petersen, the wife’s brother, was excluded. It contained extensive personal history, including detail of shared cooking arrangements in Europe in 2006–2007, and was characterised by gratuitous commentary about the husband’s career and ambition (at [82]–[85]).
The affidavits of Ms Suzanne Petersen (the wife’s mother, admitted due to her active involvement and at the husband’s request for cross-examination: at [77]–[78]), Ms Curtis (treating psychologist, admitted for currency of engagement: at [81]), Dr Joyce (paediatrician, clearly relevant to a medical dispute: at [87]), and Dr Carrillo (general practitioner, relevant to the same dispute: at [90]) were received.
3.3 Outcome
Of 25 proposed witnesses, the affidavits of 16 were not received into evidence (at [92]). The trial proceeded with the evidence of the parties, six professional witnesses, and one lay witness for each side.
4. Analysis of the Court’s Reasoning
4.1 The “prospective and predictive exercise”
O’Brien J’s reasoning is anchored in the characterisation of parenting orders as a “prospective and predictive exercise” (at [13]). The Court’s task is to determine what arrangements will best serve the children’s interests going forward, informed by relevant past events but not overwhelmed by them. “Cradle to grave” affidavits are rarely informative for that purpose.
4.2 The distinction between admissibility and probative value
The relaxed evidentiary provisions of s 102NL allow opinion and hearsay evidence in parenting proceedings. O’Brien J was at pains to emphasise that admissibility does not equate to relevance or probative value (at [12]). This is a point of general application. The fact that evidence may be received does not mean it should be. The gateway of admissibility is necessary but not sufficient.
4.3 The problem with lay opinion evidence
The judgment draws a clear line between lay opinion and expert opinion. A friend’s view that the husband is a good father, a brother-in-law’s assessment of the husband’s career ambition, or a neighbour’s impression of the wife’s parenting are, in practical terms, testimonials. They carry no weight in a forensic exercise where the Court has the benefit of expert evidence from a Single Expert Witness, a family therapist, and relevant treating professionals. As O’Brien J noted, the distinction identified in Makita at [85] between unqualified lay opinion and expert evidence remains critical (at [12]).
4.4 The “forensic disadvantage” test
A notable feature of the judgment is the role played by the opposing party’s position in the admissibility determination. In several instances, the Court admitted evidence where the opposing counsel identified a forensic disadvantage in not being able to cross-examine the witness. This arose with Ms Michelle Bailey (at [61]), Ms Suzanne Petersen (at [77]), Ms Curtis (at [80]), and Mr Visser (at [68], though there the wife’s counsel did not perceive disadvantage and the affidavit was admitted on other grounds). Where neither party perceived a forensic need for the evidence, exclusion followed.
4.5 The 220 photographs
O’Brien J’s observation about the 220 “happy photographs” annexed to the parties’ affidavits (at [27]) is a pointed illustration. No photograph of a child looking happy has probative value in proceedings where both parents are acknowledged to be devoted and competent. While self-represented litigants might mistakenly think such material serves a forensic purpose, the Court observed that “there is frankly no excuse for lawyers seeking to adduce them into evidence.”
5. Assessing the Consequences of Non-Compliance
O’Brien J identified three categories of consequence flowing from the failure to exercise independent forensic judgment on evidence.
5.1 Costs to the parties
The parties incurred unnecessary costs in the preparation, drafting, settling, filing and serving of 16 affidavits that were ultimately excluded (at [95]). Each affidavit involved time spent by the deponent in preparation, time spent by the lawyer in settling and filing, and associated court filing fees. The costs extend to the preparation of cross-examination plans for witnesses who were never called.
5.2 Delay to the parties
The inflated witness list drove an estimate of seven trial days. That estimate in turn limited the listing options available, such that earlier dates that would otherwise have been utilised could not be (at [96]). The parties’ own progress to trial was thereby delayed.
5.3 Impact on other litigants
The seven days allocated to the matter could not be allocated to other families (at [97]). This is a point of systemic significance. Court time is a finite public resource. Its inefficient consumption by one matter has a direct and measurable impact on every other matter awaiting hearing.
6. Worked Example: Applying the Principles
Consider a hypothetical parenting dispute with the following features. The parties agree that each is a competent parent. The dispute concerns the division of time and a disagreement about schooling. Each party proposes to call five lay witnesses comprising family members and friends. The single expert has provided a report. A family therapist has been appointed.
6.1 From the perspective of the party proposing the evidence
The practitioner must undertake a rigorous assessment of each proposed witness before any affidavit is drafted. The questions to ask are:
First, what is the matter in issue to which this witness’s evidence is directed? If the answer is a generalised proposition—“my client is a good parent”—the evidence is almost certainly without probative value where that proposition is not in dispute.
Second, does this witness have direct knowledge of a fact that is genuinely contested and that cannot be established by other evidence already before the Court? If the Single Expert Witness and the parties’ own evidence already address the issue, a lay witness’s observations will add nothing.
Third, is this witness offering opinion evidence? If so, is the witness qualified to give that opinion? The unqualified opinion of a family member that a parent is “demanding” or “lacks ambition” has no forensic utility.
Fourth, will the evidence withstand the scrutiny applied by O’Brien J? Would counsel be able to articulate, with precision, the probative value of the evidence if required to do so by the Court?
6.2 From the perspective of the party opposing the evidence
The practitioner should consider whether there is a genuine forensic disadvantage in the evidence being excluded. If the answer is no—if the evidence, even if admitted, would not affect the outcome—the practitioner should say so. This is what occurred in several instances in Bailey and Petersen (see, for example, at [68] where counsel for the wife confirmed no forensic disadvantage in excluding Mr Visser’s evidence).
Conversely, where the opposing party’s witness has made allegations that require testing, the practitioner should identify the forensic disadvantage of exclusion. This is what occurred with Ms Michelle Bailey (at [61]) and Ms Suzanne Petersen (at [77]), where opposing counsel’s submission that exclusion would cause forensic disadvantage contributed to the evidence being admitted.
7. Practitioner Guidance: A Step-by-Step Framework
The following framework, derived from the principles stated in Bailey and Petersen, is applicable to any proceedings in which a practitioner is considering what evidence to file.
Step 1: Identify the matters in issue.
Before any affidavit is drafted, the practitioner must clearly identify the matters actually in dispute. As O’Brien J observed, this must occur at an early stage and before trial affidavits are prepared, “for obvious reasons” (at [10]).
Step 2: Assess each proposed witness against the issues.
For each proposed witness, the practitioner must determine whether their evidence is directed to a matter genuinely in issue, whether it is relevant and of probative value, and whether it is duplicative of evidence already before the Court.
Step 3: Exercise independent forensic judgment on client-drafted material.
Where clients or witnesses have prepared initial drafts of affidavits, the practitioner has a duty to review, edit, and if necessary refuse to file that material. The duty extends to the “deletion of inadmissible, irrelevant, or gratuitous content” and further to “a refusal by the lawyer to file the affidavit if it is of no relevance or probative value” (at [26]).
Step 4: Remove all material without probative value.
This includes, by way of non-exhaustive example: happy photographs of children (at [27]); testimonial-style character evidence; gratuitous commentary about the other party’s career, ambition or personality; submissions disguised as evidence (at [48]); and historical detail unconnected to any matter in issue (at [82]).
Step 5: Communicate the professional obligation to the client.
As O’Brien J observed at [100], “the requirement to adhere to clear professional obligations is a complete answer to many of the demands made by clients.” The practitioner should explain to the client that filing irrelevant evidence will not assist their case, will increase costs, and may delay the hearing. The professional obligation provides the basis for that conversation and, if necessary, for acting contrary to the client’s wishes.
Step 6: Apply the proportionality principle.
The cost and time involved in the evidence must be proportionate to the importance and complexity of the matters in dispute (s 95(2)(e)). In a case where the core issues are narrow, a large number of witnesses is unlikely to be proportionate.
8. Evidence and Arguments Available to Each Side
8.1 For the party seeking to adduce lay evidence
The strongest argument for admission arises where the opposing party would suffer a forensic disadvantage from exclusion. This occurred in Bailey and Petersen with the parties’ mothers (at [61], [77]). The lay witness must have direct, relevant knowledge of a contested matter that is not adequately addressed by other evidence. Frequency and recency of contact with the children will strengthen the case for admission. Evidence addressing a specific concern raised by the Single Expert Witness is more likely to be admitted (at [60]).
8.2 For the party opposing the evidence
The following arguments, each grounded in Bailey and Petersen, are available:
(a) The evidence is duplicative: the same matters are addressed in the party’s own affidavit and/or the expert evidence (at [45]).
(b) The evidence is opinion evidence from an unqualified lay witness and lacks the indicia required for expert opinion: Makita at [85]; Bailey and Petersen at [12].
(c) The witness has limited contact with the children, reducing the weight and relevance of any observations (at [45], [47]).
(d) The affidavit contains submissions rather than evidence (at [48]).
(e) There is no forensic disadvantage from exclusion because the matters addressed are not in dispute or are adequately addressed elsewhere (at [68]).
9. Key Takeaways for Legal Practice
1. The duty to exercise independent forensic judgment is mandatory. It is not diminished by client instructions, client-drafted affidavits, or the pressures of busy practice (at [22]–[23]).
2. Identify the issues before drafting evidence. The matters in issue must be clearly identified at an early stage and before trial affidavits are prepared (at [10]).
3. Admissibility does not equate to relevance or probative value. The relaxed evidentiary regime in parenting proceedings does not exempt evidence from scrutiny for relevance and probative value (at [12]).
4. Lay opinion evidence is rarely of probative value where the Court has the benefit of expert evidence. The distinction in Makita between qualified and unqualified opinion evidence remains critical.
5. Testimonials and character references do not assist. Evidence that a parent is “a good father” or “a caring mother” has no forensic utility where competent parenting is not in dispute.
6. The professional obligation is a tool, not a burden. It provides the complete answer to demanding clients (at [100]). Adherence to it will “alleviate the pressure perceived by a practitioner more often than it will exacerbate it.”
7. Consequences extend beyond the parties. Inflated trial estimates consume finite court resources and delay other families’ access to justice (at [97]–[98]).
8. The principles are of general application. While the judgment arises in the family law jurisdiction, the duties described apply to all lawyers in all jurisdictions. The obligation to confine a hearing to the real issues and present the case as quickly and simply as is consistent with its robust advancement is universal.
10. Conclusion
Bailey and Petersen is a judgment that every practitioner should read. Its significance extends well beyond family law. It is a clear, authoritative statement that lawyers are not obliged—and are in fact prohibited—from acting as conduits for their clients’ every wish in relation to evidence. The independent forensic judgment of the lawyer is not a discretionary add-on; it is a professional obligation.
The judgment serves as a reminder that the pressures of practice—demanding clients, tight deadlines, the temptation to file everything and let the Court sort it out—do not excuse a failure to discharge that obligation. As O’Brien J observed, with proper regard to the principles summarised in the judgment, the process of excluding 16 of 25 proposed witnesses “should have been entirely unnecessary” (at [94]). The affidavits eventually excluded should never have been filed.
For practitioners, the practical message is straightforward. Identify the issues early. Assess each piece of evidence against those issues. Remove what is irrelevant. Refuse to file what is gratuitous. Explain the professional obligation to the client. The obligation is not a constraint on effective advocacy; it is a component of it.
