McEwan v Commissioner of Taxation [2026] QSC 42

ESTOPPEL - ESTOPPEL BY JUDGMENT - ISSUE ESTOPPEL - GENERAL PRINCIPLES - where the applicant was prosecuted by the eighth, ninth and eleventh defendants (State defendants) for a charge of fraud under s 408C(1) of the Criminal Code (Qld) (State Charge) - where the prosecution of the State Charge was discontinued - where the bringing and continuing of the State Charge is the basis for the applicant's claims in this proceeding for malicious prosecution and misfeasance in public office against the State defendants - where the applicant was also prosecuted under ss 11.1 and 134.2(1) of the Criminal Code (Cth) (Commonwealth Charge) by the third defendant (CDPP) - where in ordering the permanent stay of the prosecution of Commonwealth Charge the Court made findings relating to prosecution of the State Charge (State Charge Findings) - where the applicant submits that the State defendants are bound by the State Charge Findings and are estopped from pleading a defence or adducing evidence in this proceeding which would contradict the State Charge Findings on the basis that the CDPP was their privy in interest in opposing the application for a permanent stay of the prosecution of the Commonwealth Charge - whether the State defendants are a privy in interest of the CDPP in relation to the State Charge Findings

PROCEDURE - CIVIL PROCEEDINGS IN STATE AND TERRITORY COURTS - SEPARATE DECISION OR DETERMINATION OF QUESTIONS AND CONSOLIDATION OF PROCEEDINGS - SEPARATE DECISION OR DETERMINATION - GENERALLY - where the applicant applied against the State defendants for an order pursuant to r 483 Uniform Civil Procedure Rules 1999 (Qld) for the separate determination of questions in the proceeding - whether it is just and convenient for the order to be made

Uniform Civil Procedure Rules 1999 (Qld), rr 482, 483

A v New South Wales (2007) 230 CLR 500; [2007] HCA 10, applied

Advance Traders Pty Ltd v McNab Constructions Pty Ltd [2011] QSC 212, applied

McEwan v Commissioner of Taxation [2022] QSC 279, cited

McEwan v Commissioner of Taxation [2025] QCA 48, cited

McEwan v Rains & Ors [2023] QCA 135, cited

R v Clarke (a pseudonym) (No 9) [2025] QSCPR 17, cited

Ramsay v Pigram (1968) 118 CLR 271; [1968] HCA 34, applied

Tomlinson v Ramsey Food Processing Pty Ltd (2015) 256 CLR 507; [2015] HCA 28, applied

Z M Rowling (solicitor) for the first to seventh defendants

D M Favell for the eighth, ninth and eleventh defendants

Australian Government Solicitor for the first to seventh defendants

Crown Solicitor for the eighth, ninth and eleventh defendants.

Application for the determination of a separate question

[1] The plaintiff has applied against the eighth, ninth and eleventh defendants (State defendants) for the determination of a separate question in this proceeding.[1] Before setting out the proposed separate question it is necessary to briefly set out the circumstances in which the application has been brought.

[2] On 3 October 2025, Smith J permanently stayed the prosecution of the plaintiff by the third defendant (CDPP) for an offence under ss 11.1 and 134.2(1) of the Criminal Code (Cth) of attempting to dishonestly obtain a financial advantage from a Commonwealth entity (Commonwealth Charge).[2] The allegation founding the Commonwealth Charge was that, in 2017, the plaintiff had authorised the lodgement of a research and development tax offset claim for the financial year 2016/2017 on behalf of one of her associated companies. It was alleged that the tax offset claim falsely stated the amount of research and development expenditure the associated company had incurred and which it relied on in seeking a refund from the Australian Taxation Office (ATO).

[3] The plaintiff was also prosecuted for a charge of fraud under s 408C(1) of the Criminal Code (Qld) brought against her on 22 August 2018 (State Charge). The prosecution of the State Charge did not ultimately proceed. On 12 May 2021, the Crown entered a nolle prosequi in respect of that charge and the prosecution was discontinued. The bringing and continuing of the State Charge is the basis for the plaintiff's claims in this proceeding for malicious prosecution and misfeasance in public office against the State defendants, as well as the first to seventh defendants (Commonwealth defendants).

[4] In the reasons for staying the prosecution of the Commonwealth Charge, Smith J also made findings relating to the prosecution of the State Charge (State Charge Findings). The plaintiff now asserts that the State defendants are bound by the State Charge Findings. She submits that they are not permitted to plead a defence or adduce evidence in this proceeding which would contradict those findings.

[5] Against that background, the plaintiff applies for the following orders against the State defendants:

"1. Pursuant to r 483 of the [UCPR] the Court order for decision and statement of case for opinion as to whether each of the State defendants are a Privy of Interest in the [Clarke Decision] as it relates to the State Charge;

On the basis the answer to the Question (1) is 'Yes'

1.1 the effect and relevance of an issue estoppel as it relates to the cause of action for malicious prosecution and misfeasance in public office in these proceedings for the failed State charge proceedings;

1.2 the findings that relate to the State charge relied on are set out in the Clarke Decision, many of those key issues are identified in the Plaintiff's Reply to the State defendants defences upon which issue estoppel is claimed."

[6] After the hearing of the application, the plaintiff filed a further affidavit and outline of submissions.[3] I considered those documents in determining the application.

The relevance of the State Charge Findings to the present proceeding

[7] The circumstances leading to the commencement of this proceeding were summarised succinctly by Freeburn J in an earlier interlocutory decision:[4]

"A broad collection of entities, called Brisbane Angels, had an interest in providing funds for start-up investment projects, with a particular focus in biotechnology. The Brisbane Angels decided to invest $185,000 in a weight loss project operated by Ms McEwan (and entities associated with her). That project was called the Carbstarver project. Ms McEwan says she reconciled her use of the $185,000 investment by means of an acquittal spreadsheet on 16 August 2017. A year later, however, Ms McEwan was charged with fraud. She was committed for trial in the District Court on 10 December 2019. No case submissions were made on 8 July 2019, 19 March 2020, and 28 August 2020. Eventually, on 12 May 2021, a nolle prosequi was entered."

[8] By way of summary, the plaintiff pleads the following matters in support of her claims for malicious prosecution and misfeasance in public office:

(a) the investigation by the second defendant, Mr Rains (an investigator employed by the ATO), of a claim for a research and development tax offset made by one of the plaintiff's associated entities, including the collation of evidence which was improperly provided to the Queensland Police Service (QPS) and later relied on in the prosecution of the State Charge;[5]

(b) the entry into a joint agency agreement (JAA) between the ATO and the QPS for the investigation of Ms McEwan for suspected offending, including the offending which became the subject of the State Charge, with Mr Rains assuming the role of lead investigator for the State Charge and Officer Adrian Holt of the QPS assuming the role of investigator on behalf of the QPS;[6]

(c) the laying of the State Charge against the plaintiff on 22 August 2018, by Officer Holt at the direction of the ATO;[7]

(d) that the QP9 prepared by Officer Holt in relation to the State Charge was misleading because it failed to make reference to relevant and exculpatory information and documents that were in the possession of Mr Rains and the ATO at the time;[8]

(e) conduct by Mr Rains during the prosecution of the State Charge, relevantly including the preparation of a statement of Ms Akeroyd (Akeroyd Statement) which he knew to be false, and the inclusion of that statement in the brief of evidence for the State Charge;[9]

(f) that Officer Holt received the Akeroyd Statement from Mr Rains, knew that it was false and knew that it had been included in the brief of evidence for the State Charge;[10]

(g) conduct by Officer Holt in taking statements from representatives of Brisbane Angels, relevantly including statements from Mr McTaggart and Mr Hoult which contained inadmissible hearsay;[11]

(h) conduct by the ninth defendant, Ms McGregor (a prosecutor employed by the Office of the Director of Public Prosecutions (Qld) (QDPP)), at the committal hearing for the State Charge on 10 December 2019, including reliance upon the statement of Mr McTaggart containing hearsay and the failure to tender key exculpatory documents;

[9] The State Charge Findings relevantly include findings that:

(a) the JAA was a misleading document that directly led to the creation of the QP9;[14]

(b) the QP9 was a misleading document;[15]

(c) Officer Holt knew about the Akeroyd Statement. He was most likely given it by Mr Rains. The fact that there was a false statement would have been the subject of discussion between them;[16]

(d) Ms McGregor did not draw the court's attention to relevant matters and did not tender relevant evidence at the committal hearing for the State Charge;[17]

(e) reasonable no-case submissions concerning the State Charge were ignored or given insufficient consideration;[18]

(f) the plaintiff had no case to answer on the State Charge;[19]

(g) the State Charge was continued for an unlawful collateral purpose.[20]

[10] The plaintiff accepts that the State defendants were not parties to the prosecution of the Commonwealth Charge or the application to stay that prosecution.[21] Nevertheless, she submits that the State Charge Findings raise issue estoppels that bind the State defendants on the basis that the CDPP was their privy in interest in opposing her application for a permanent stay of the prosecution of the Commonwealth Charge. That is the issue she seeks to have resolved through the determination of the proposed separate question.

483 Order for decision and statement of case for opinion

(1) The court may make an order for the decision by the court of a question separately from another question, whether before, at, or after the trial or continuation of the trial of the proceeding.

(2) The Supreme Court, other than the Court of Appeal, may also state a case for the opinion of the Court of Appeal.

[12] The term "question" in r 483 is defined to include "a question or issue in a proceeding, whether of fact or law or partly of fact and partly of law, and whether raised by pleadings, agreement of parties or otherwise": see r 482.

[13] The approach which the court should take when considering such an application was considered by Boddice J (as his Honour then was) in Advance Traders Pty Ltd v McNab Constructions Pty Ltd:[22]

"[10] The rule is intended to provide for the determination of an issue or issues the resolution of which is likely to lead to substantial savings and expense. Whether an order is made is subject to the exercise of the discretion of the Court. In exercising that discretion, a relevant consideration is whether it would be convenient to determine first the issues raised, and, in particular, whether the successful determination of the separate issues would:

(a) relieve the parties and the Court of the need to otherwise consider a significant volume of documents;

(b) avoid the need for the Court at trial to consider expert evidence;

(c) avoid, or at the very least reduce, the necessity for a lengthy trial.

[11] In Reading Australia Pty Ltd v Australian Mutual Provident Society & anor, Branson J said, in respect of a provision in the Federal Court Rules, which is materially in identical terms to r 483:

(b) a question can be the subject of an order for a separate decision under 0 29 r 2 even though a decision on such a question will not determine any of the parties' rights (Landsal Pty Ltd (in liq) v REI Building Society at FCR 425; ALR 647);

(c) however, the judicial determination of a question under 0 29 r 2 must involve a conclusive or final decision based on concrete and established or agreed facts for the purpose of quelling a controversy between the parties (Bass v Permanent Trustee Co Ltd (1999) 198 CLR 334; 161 ALR 399; [1999] HCA 9 at [45]);

(d) where the preliminary question is one of mixed fact and law, it is necessary that the question can be precisely formulated and that all of the facts that are on any fairly arguable view relevant to the determination of the question are ascertainable either as facts assumed to be correct for the purposes of the preliminary determination, or as agreed facts or as facts to be judicially determined (Jacobson v Ross [1995] VicRp 24; [1995] 1 VR 337 at 341, referring to Nissan v Attorney-General [1969] UKHL 3; [1970] AC 179 at 242-3; at 663-4 per Lord Pearson; at [53]);

These factors have been identified as being relevant in considering the operation of r 483. Ultimately, the issue for the Court, in determining whether to exercise the discretion and make an order for separate determination, is whether it is 'just and convenient' for the order to be made.

[15] Whilst courts are now more liberal in their consideration of whether to order the separate determination of preliminary questions, caution must be exercised before making such an order having regard to the risk of being too readily tempted by the promise of a saving of time and costs whereas the outcome results in time wasting and an increase in costs whilst also fragmenting and delaying the outcome."

[14] The plaintiff submits that the answer to the proposed separate question will affect the way that the State defendants can defend this proceeding and, consequently, the evidence which they may adduce at trial. If the court determines that the State defendants are bound by the State Charge Findings, the plaintiff will apply to strike out those parts of the State defendants' amended defence which contradict those findings. This would narrow the scope of the issues in dispute and be likely to reduce the length of the trial. The plaintiff submits that if the question remains unresolved at the commencement of the trial, the proceeding might be derailed by the need to determine the question in the context of deciding objections to evidence.

[15] The State defendants oppose the application. They submit that a determination of the proposed separate question is unlikely to reduce the scope of the proceeding or the length of any trial.

[16] That submission requires consideration of the elements of the cause of action for malicious prosecution. To succeed on such a claim, the plaintiff must establish four things: (1) that the prosecution of the State Charge was initiated against her by the State defendants; (2) that the prosecution of the State Charge terminated in her favour; (3) that, in bringing and continuing the State Charge, the State defendants acted maliciously; and (4) that the State defendants acted without reasonable and probable cause. Only elements (3) and (4) are in issue in this proceeding.

[17] The State defendants submit that, if accepted, the State Charge Findings are perhaps capable of establishing that the State Charge was brought and continued without reasonable and probable cause. However, even taken at their highest, the findings could not, of themselves, establish malice on the part of the State defendants. To constitute malice, the dominant purpose of the State defendants must have been a purpose other than the proper invocation of the criminal law.[23] The State defendants submit that it will be necessary for the trial judge to consider the circumstances in which the State Charge was brought and Officer Holt's reasons for doing so, as well as the circumstances in which the prosecution of the State Charge was pursued by the QDPP and Ms McGregor, and any explanation from Ms McGregor as to her conduct in pursuing that prosecution. The State defendants submit this will require the trial judge to hear all the evidence about the State Charge because it is not possible to quarantine the question of malice from that of reasonable and probable cause.[24] The same evidence is likely to be relevant to both issues.

[18] The State defendants submit that the determination of a separate question is not the proper vehicle for the plaintiff to seek the result she contends for; that is, estopping the State defendants from arguing against the State Charge Findings. The proper approach would be for the plaintiff to seek to strike out the parts of the State defendants' amended defence which she says contradict those findings. At the hearing of the present application, counsel for the State defendants accepted that if that course is taken, to determine the strike out application, the court would be required to decide whether the State Charge Findings bind the State defendants in these proceedings.

[19] The Commonwealth defendants also oppose the application. At some stage, the effect of Smith J's findings on the Commonwealth defendants' defence to this proceeding will have to be addressed. Like the State defendants, the Commonwealth defendants submit the plaintiff should raise the question of issue estoppel in the context of an application to strike out parts of their defence which contradict the relevant findings. They submit strike out applications against both groups of defendants should progress in a coordinated fashion to avoid fragmentation of this proceeding.

[20] As the proposed separate question is directed only to the State defendants, I accept that there is a risk of the proceeding being fragmented if the issue raised by the question is determined now. I am also conscious of the need to exercise caution in allowing a question to be determined separately and in advance of the other issues in a proceeding.

[21] Nevertheless, for reasons which follow, I have concluded that the answer to the question posed by paragraph 1 of the plaintiff's amended application must be "No". On that basis, the State defendants are not bound by any issue estoppel arising from the State Charge Findings. It would waste the time and resources of the parties and the court to require that the plaintiff bring a strike out application against the State defendants before that issue is determined.

[22] It may be that this judgment is appealed. If so, there will be some delay before a final determination is made concerning the State defendants' entitlement to plead facts and lead evidence that might contradict the State Charge Findings. However, if that occurs it should not delay the whole proceeding. If there is an appeal against this judgment, I see no reason why steps could not be taken in the meantime to address the effect of Smith J's findings on the conduct of the Commonwealth defendants' defence to this proceeding. The position of the Commonwealth defendants is not necessarily the same as that of the State defendants. The conclusion I have reached at [21] above outweighs what might, in other circumstances, seem the more conventional approach of dealing with the effect of findings made in the stay application for both groups of defendants at the same time.

[23] I am satisfied that, in the present circumstances, it is just and convenient to answer the separate question at this stage of the proceeding.

[24] The principle which governs the determination of the separate question was explained by the High Court in Tomlinson v Ramsey Food Processing Pty Ltd.[25]

[25] Before turning to the High Court's discussion of the principle itself, it is useful to note the facts of that case. Mr Tomlinson worked at an abattoir operated by the respondent to the appeal (RFP). He and the other workers were told that their employment by RFP had been discontinued and that they would instead be employed by a labour hire company which provided labour services to RFP. Two years later the workers were told that the labour hire company was no longer providing labour to RFP and the labour hire company was unable to offer them ongoing employment. The workers (including Mr Tomlinson) complained to the Fair Work Ombudsman. The Ombudsman then brought a proceeding against RFP in the Federal Court under the Fair Work Act 2009 (Cth) to enforce that Act and awards made under the Workplace Relations Act 1996 (Cth). The Workplace Relations Act conferred power on the Federal Court to order that a person found to be an "employer" was to pay an amount to a person found to be an "employee". The Ombudsman alleged that RFP had been the employer of the redundant workers, that it had been bound by the terms of a meat industry award, and that as employer it had failed to pay the workers amounts due to them on termination of their employment. The workers were not parties to the proceeding. The Federal Court held that RFP had been the true employer, that everything done by the labour hire company had been done on behalf of RFP, and that the interposition of the labour hire company had been a sham. RFP was ordered to pay certain amounts to the workers.

[26] Mr Tomlinson later brought proceedings against RFP in the District Court of New South Wales claiming damages in negligence for a personal injury he had sustained while working at the abattoir. He contended that the labour hire company had been his employer but that RFP, as the party in control of the workplace, owed him a duty of care akin to that of an employer. If RFP had been Mr Tomlinson's employer at the time of the injury, he would have been prevented from bringing the claim, or from recovering damages, by New South Wales legislation governing workplace injuries. RFP pleaded that Mr Tomlinson was estopped by the orders made in the Federal Court proceeding from denying that RFP had been his employer at the relevant time.

[27] The High Court held that the declarations and orders made in the proceeding brought by the Ombudsman did not create an issue estoppel binding on Mr Tomlinson because, in performing his statutory function of commencing enforcement proceedings under the Fair Work Act 2009 (Cth), the Ombudsman did not represent the legal interests of Mr Tomlinson, in the sense which gave rise to an estoppel. The Ombudsman had been acting pursuant to his statutory power to enforce the award and was not enforcing Mr Tomlinson's entitlements on his behalf.

[28] The question fell to be determined according to the principle, stated in Ramsay v Pigram,[26] that the "basic requirement of a privy in interest is that the privy must claim under or through the person of whom he is said to be a privy".

[29] Before explaining that principle, the majority of the High Court in Tomlinson made the following observations more generally about the place of issue estoppel in Australian law:[27]

"An exercise of judicial power, it has been held, involves 'as a general rule, a decision settling for the future, as between defined persons or classes of persons, a question as to the existence of a right or obligation, so that an exercise of the power creates a new charter by reference to which that question is in future to be decided as between those persons or classes of persons'. The rendering of a final judgment in that way 'quells' the controversy between those persons. The rights and obligations in controversy, as between those persons, cease to have an independent existence: they 'merge' in that final judgment. That merger has long been treated in Australia as equating to 'res judicata' in the strict sense.

Estoppel in relation to judicial determinations is of a different nature. It is a common law doctrine informed, in its relevant application, by similar considerations of finality and fairness. Yet its operation is not confined to an exercise of judicial power; it also operates in the context of a final judgment having been rendered in other adversarial proceedings. It operates in such a context as estoppel operates in other contexts: as a rule of law, to preclude the assertion of a right or obligation or the raising of an issue of fact or law.

Three forms of estoppel have now been recognised by the common law of Australia as having the potential to result from the rendering of a final judgment in an adversarial proceeding. The first is sometimes referred to as 'cause of action estoppel'. Estoppel in that form operates to preclude assertion in a subsequent proceeding of a claim to a right or obligation which was asserted in the proceeding and which was determined by the judgment. It is largely redundant where the final judgment was rendered in the exercise of judicial power, and where res judicata in the strict sense therefore applies to result in the merger of the right or obligation in the judgment. The second form of estoppel is almost always now referred to as 'issue estoppel'. Estoppel in that form operates to preclude the raising in a subsequent proceeding of an ultimate issue of fact or law which was necessarily resolved as a step in reaching the determination made in the judgment. The classic expression of the primary consequence of its operation is that a 'judicial determination directly involving an issue of fact or of law disposes once for all of the issue, so that it cannot afterwards be raised between the same parties or their privies'. The third form of estoppel is now most often referred to as 'Anshun estoppel', although it is still sometimes referred to as the "extended principle" in Henderson v Henderson. That third form of estoppel is an extension of the first and of the second. Estoppel in that extended form operates to preclude the assertion of a claim, or the raising of an issue of fact or law, if that claim or issue was so connected with the subject matter of the first proceeding as to have made it unreasonable in the context of that first proceeding for the claim not to have been made or the issue not to have been raised in that proceeding. ..."

[30] As the majority observed,[28] each those three forms of estoppel has the potential to preclude the raising of an issue of fact or law, between parties to a proceeding or their privies. However, there is one principle which governs the identification of privies for the purpose of all three forms of estoppel.

[31] The privity principle stated in Ramsay, and explained in Tomlinson, is based on the maxim that a person who takes the benefit should also have to bear the burden.[29] A party to a later proceeding can be privy in interest with a party to an earlier proceeding on either of two bases.[30] As I understand the plaintiff's argument, only the first basis is relevant for the purposes of the present application. That is, where the party to the later proceeding (in the present case, the State defendants) had some legal interest in the outcome of the earlier proceeding which was represented by the putative privy (in the present case, the CDPP). The interest in the earlier proceeding must be a legal interest. An economic or other interest in the outcome of the earlier proceeding is insufficient.[31] Further, as Nettle J observed in separate concurring reasons, the party to the later proceeding must share the same legal interest in the earlier proceeding as the putative privy. It is not enough to establish that the party to the later proceeding and the putative privy had different legal interests in the earlier proceeding, even if those different interests were productive of "a unity of outcome".[32]

[32] The majority in Tomlinson also addressed the application of the privity principle in circumstances where the party to the earlier proceeding is a statutory-officer holder (as the CDPP is in this case). Relevantly, the majority noted that, other than where the office-holder is specifically required or authorised by statute to make a claim as a representative of another person, the office-holder would not ordinarily be required by statute to consider interests of the person beyond those interests which fall within its own statutorily defined area of responsibility. The office-holder might not even be permitted to consider broader interests of the other person, because to do so might conflict with the proper discharge of that statutory responsibility.[33] Were the party to the later proceeding to be privy in interest with the office-holder for the purpose of the common law doctrine of estoppel, pursuit of a claim by the statutory entity might foreclose not only the pursuit of the same and other claims by that person, but also the raising by that person of issues of fact or of law in defence of claims brought against that person. This would have the real potential to occasion injustice to that person. The majority in Tomlinson concluded that if such a result is not imposed by the statute under which the office-holder acts, then it should not be superimposed by the common law of estoppel.[34]

The CDPP was not the privy in interest of the State defendants

[33] The plaintiff advances her argument that the CDPP was the State defendants' privy in interest on two bases.

[34] First, the plaintiff submits that counsel who appeared for the CDPP, Mr Rains and the Australian Taxation Office in earlier proceedings in this court seeking the permanent stay of the prosecution of the Commonwealth Charges also appeared for the State defendants.

[35] On 15 September 2022, I heard an application to set aside subpoenas which the plaintiff had issued to nine persons to give evidence at the hearing of the earlier stay application. The subpoenaed witnesses included Officer Holt and Ms McGregor. At the hearing of the application to set aside the subpoenas, counsel appeared for the CDPP, Mr Rains and the Australian Tax Office who were the three named respondents to the earlier stay application. The plaintiff submits that because the relief sought at that hearing included setting aside the subpoenas addressed to Officer Holt and Ms McGregor, counsel who appeared must have appeared on behalf of the State defendants.

[36] I do not accept that submission. The ex-tempore reasons I gave for setting aside the subpoenas recorded a submission by the plaintiff at that hearing that, by filing and arguing the applications to set aside the subpoenas, the legal representatives for the three respondents to the earlier stay application were acting for some of the subpoenaed witnesses without instructions. I rejected that submission, finding that the respondents to the earlier stay application had standing to apply to set aside the subpoenas. The applications had not been made by or on behalf of the subpoenaed witnesses for whom the legal representatives for the respondents did not act. Nothing said in the decision on the plaintiff's appeal from my orders setting aside the subpoenas affects that finding.[35] I adhere to that finding on the present application.

[37] In any event, the material on the present application establishes that, by the time the subsequent stay application was heard by Smith J, Crown Law acted for Ms McGregor in seeking to set aside or limit the scope of a further subpoena the plaintiff had served. Mr Prior deposed to having received instructions to act on behalf of Ms McGregor in that respect in or about November 2023.[36] On 28 November 2023, Mr Prior instructed Ms Amos of counsel on behalf of Ms McGregor at a pre-trial hearing before Smith DCJ (as his Honour was then) on the indictment containing the Commonwealth Charge.[37] That is clear evidence that counsel who appeared for the CDPP on the stay application heard by Smith J did not appear for the State defendants.

[38] Secondly, the plaintiff submits that, in circumstances where one of the bases upon which she sought to stay the prosecution of the Commonwealth Charge was that the prosecution of the State Charge amounted to an abuse of process, the State defendants had a legal interest in the stay application. She submits that the State defendants had a legal interest in defending their conduct in bringing and pursuing the State Charge, and the CDPP represented that interest in the hearing of the stay application.

[39] I do not accept that submission. In responding to the application to stay the prosecution of the Commonwealth Charge, the CDPP was not acting "under or through" or "on behalf of" the State defendants. Instead, the CDPP was acting pursuant to her statutory power to enforce the Criminal Code (Cth). That power was not derived from the State defendants or any interest they held in the stay application.

[40] In exercising her statutory power, the CDPP did not represent the legal interests of the State defendants, in the sense which gives rise to an estoppel, by opposing the stay application. The fact that, in arguing for the stay, the plaintiff impugned the conduct of Officer Holt and Ms McGregor concerning the State Charge makes no difference to that conclusion. It did not result in the CDPP and the State defendants having the same legal interest in the stay application. The CDPP's legal interest in the stay application was in the continuation of the prosecution of the Commonwealth Charge pursuant to her statutory power to enforce the criminal law. The State defendants did not share that legal interest. Consistently with this, the CDPP was not required consider any interest the State defendants might have had in the outcome of the stay application. At most, the CDPP and the State defendants had different legal interests productive of a unity of outcome. As Nettle J explained in Tomlinson (see [31] above), that is not sufficient.

[41] Although the plaintiff issued subpoenas to Officer Holt and Ms McGregor, none of the State defendants had any capacity to control the prosecution of the Commonwealth Charge, or to appear in response to the plaintiff's application to stay that prosecution. The State defendants did not have any opportunity to exercise control over the presentation of evidence or the making of arguments in the stay application. In those circumstances, it would be unjust for the State defendants to be precluded in this proceeding from asserting what they claim to be the truth regarding the bringing and continuation of the State Charge.[38]

The answer to the question posed in paragraph 1 of the plaintiff's amended application filed 27 February 2026 is "No". It is unnecessary to answer the questions posed in paragraphs 1.1 and 1.2 of the amended application.

[1] Uniform Civil Procedure Rules 1999 (UCPR), r 483.

[2] R v Clarke (a pseudonym) (No 9) [2025] QSCPR 17 (Clarke Decision).

[4] McEwan v Commissioner of Taxation [2022] QSC 279, [1]. This summary was recently adopted in the decision of the Court of Appeal in McEwan v Commissioner of Taxation [2025] QCA 48, [4].

[5] Sixth Revised Statement of Claim filed on 18 November 2025 (Court document 333) (6RSOC), [8]-[12], [21.2]-[21.3].

[6] 6RSOC, [14.1]-[14.5], [17], [17.2].

[12] 6RSOC, [22.3]-[22.4], [60](b)-(c).

[13] 6RSOC, [22.5], [23], [24], [55], [55.1], [56](a), [59.1].

[15] Clarke Decision, [1416], [1976].

[16] Clarke Decision, [1752], [1756], [1758].

[17] Clarke Decision, [1549]-[1552], [1994].

[18] Clarke Decision, [1986], [2061](b).

[20] Clarke Decision, [2002](h), [2061](a).

[21] Plaintiff's submissions filed 27 February 2026 (Court document 342), [19](b).

[22] [2011] QSC 212 (citations omitted).

[23] A v New South Wales [2007] HCA 10; (2007) 230 CLR 500, 531 [91].

[24] A v New South Wales [2007] HCA 10; (2007) 230 CLR 500, 531 [90].

[25] [2015] HCA 28; (2015) 256 CLR 507 (Tomlinson).

[26] [1968] HCA 34; (1968) 118 CLR 271, 279 (Ramsay).

[27] Tomlinson, 516-518 [20]-[22] (citations omitted).

[29] Tomlinson, 520-521 [28]-[30].

[31] Tomlinson, 522 [35] and 541 [105].

[35] McEwan v Rains [2023] QCA 135.

[36] Affidavit of John Laurence Prior filed by leave on 3 March 2026, [2]-[9].

[37] Affidavit of John Laurence Prior filed by leave on 3 March 2026, exhibit JLP7 (pages 26 to 36 of the exhibit bundle) and JLP 8 (pages 38 to 219 of the exhibit bundle, particularly at pages 65 to 92 and pages 109 to 118).