P v Child Support Registrar

The statutory framework 11 Before going any further, it is necessary to say something about the legislative scheme. It is described in some detail in the decision of the Full Court in C's case (at [16]-[26]). For present purposes, it is sufficient to refer to the relevant sections. They appear in Subdivision B of Division 4 of Part 5 of the Assessment Act. They deal with the determination of the percentage of care for a child to be attributed to a "responsible person", defined in s 5 of the Act to mean "a parent or non-parent carer of the child". 12 By s 50 of the Assessment Act, where the Registrar revokes a determination of a responsible person's percentage of care for a child and is satisfied that the person has had, or is likely to have, "a pattern of care" for the child during such period "as the Registrar considers to be appropriate having regard to all the circumstances" ("the care period"), the Registrar is obliged to determine the responsible person's percentage of care for the child during that period. Unless s 51 or 52 applies, the percentage must be a percentage corresponding to the actual care of the child the Registrar is satisfied the responsible person has had, or is likely to have, during the care period. 13 Section 54A, upon which P relied, states: Working out actual care, and extent of care, of a child (1) The actual care of a child that a person has had, or is likely to have, during a care period may be worked out based on the number of nights that the Registrar is satisfied that the child was, or is likely to be, in the care of the person during the care period. (2) The extent of care of a child that a person should have had, or is to have, under a care arrangement during a care period may be worked out based on the number of nights that the child should have been, or is to be, in the care of the person during the care period under the care arrangement. (3) For the purposes of this section, a child cannot be in the care of more than one person at the same time. (4) This section does not limit section 50, 51, 52 or 54. 14 It was common ground that ss 51, 52 and 54 are irrelevant. 15 Section 54F relevantly requires a determination of a parent's percentage of care made under s 50 to be revoked if the Registrar becomes aware that the care a child is receiving does not correspond with the parent's existing percentage of care and the Registrar is satisfied that the parent's cost percentage would change if the Registrar were to determine (under s 50) another percentage to be the person's percentage of care for the child. 16 In making any determination under Subdivision B, the Registrar is required to have regard to any guidelines in force under s 35N(1) of A New Tax System (Family Assistance) Act 1999 (Cth): Assessment Act, s 54E.

The AAT's decision 17 Contrary to P's contention that it should do so, the tribunal declined to apply the method for determining actual care provided by s 54A(1). The tribunal noted that the primary judge in C's case (Wigney J) had held that it was not mandatory to do so and that in a case such as this, where the child is at boarding school and not staying overnight with either parent, it is of little guidance or assistance. Indeed, the tribunal said that in these circumstances it was neither useful nor appropriate and it would be artificial and arbitrary to invoke it. 18 The tribunal rejected P's contention that A was entirely in the care of P when he was boarding because P pays or is responsible for the school fees. The tribunal explained (at [67]): If this is a contention that actual care should be assessed on nights and all nights should be attributed to the applicant while A is in boarding school, I reject it. This contention does not recognise the importance of certain aspects of care for A, other than those relating to his accommodation, food and clothing, and ignores the level of care provided by [M] during this time. She sees or speaks to A every day during the week while he is at school, is involved in parent-teacher meetings and is listed as one of A's emergency contacts. No major decisions about A's health care, medical treatment or education could be made during this period without reference to [M]. 19 The tribunal then proceeded to make an assessment of actual care without regard to s 54A(1) (or (2)). 20 Noting that "actual care" was not defined in the Assessment Act except by reference to s 54A(1), the tribunal considered that the expression should be given its ordinary meaning. 21 The tribunal appears to have accepted that during the time A was at boarding school: the school would contact both parents when the children were ill or there was some other need for them to be contacted; M had regular contact with A by telephone; M would regularly meet A for lunch and make purchases of food, toiletries and other items for him; M would take A to and from school on the weekends he spent with her; M maintained accommodation near to the school where clothing and equipment for all three children were kept. 22 The tribunal said (at [71]): The evidence is to the effect that once A commenced boarding at [the school] both parents continued to communicate with him regularly during the week. They are both involved with the school and provide emotional support to A. Their evidence on these matters was not contested. When A is not boarding, he spends alternate weekends and half the holidays with each parent. 23 The tribunal noted that P and M had shared parental responsibility for A as a result of the orders made by consent in the Federal Magistrates Court on 6 June 2011. The tribunal considered that making decisions about important life matters or having the responsibility for doing so was relevant to, though not determinative of, the question of care. 24 The tribunal concluded that, but for the question of the payment of school fees and the financial support for A while he is a boarder, P and M were "on equal footing on most aspects of [A's] care". With respect to the school fees, it found that P's mother either paid them or, at P's request, loaned money to P to pay them and that M made no contribution. It considered that this circumstance was also relevant to the assessment of care, though once again not determinative. It concluded (at [80]) that: the level of care for A as between [P] and [M] when he is boarding is weighed in favour of [P] but not significantly so. The percentage of care would have been equal but given [P] has responsibility for the fees (and has caused those fees to be paid), his contribution to the level of care is higher for the purposes of assessing care under the child support scheme during the period A is a boarder. 25 The tribunal determined that, during the period A was boarding, P contributed 60% of the care and M 40%. It explained: This takes into account that all A's expenses are paid during these periods, either by [P] or at his request, and [M] is not required to provide any financial support. It nonetheless also takes into account that [P] and [M] otherwise provide emotional support and ongoing responsibility for major decisions should they arise during the periods, in equal measure. It does not matter that no such major decisions have arisen for A during the period in question. The evidence is that if they had arisen, both [P] and [M] would have been involved in this decision-making process. 26 For the rest of the time, the tribunal found that either P or M was solely responsible for A's care, and based on the fact that they shared custody equally, it found that their respective percentage of care was 50% each. The tribunal then combined and averaged the percentages to calculate the overall percentage of care. This resulted in figures of 55% for P and 45% for M. 27 Having found that the actual care of A for the care period did not correspond with the existing determination and that this would have an impact on P's cost percentage, the tribunal revoked the existing determination under s 54F of the Assessment Act, effective from 8 January 2013, and substituted the figures mentioned in the preceding paragraph.

The nature and scope of the appeal 28 An appeal from the AAT may only be brought on a question of law: Administrative Appeals Tribunal Act 1975 (Cth) ("AAT Act"), s 44. It is the question of law which is the subject matter of the appeal. As Gummow J explained in TNT Skypak International (Aust) Pty Ltd v Federal Commissioner of Taxation (1988) 82 ALR 175 at 180-1; [1988] FCA 119 at [19]-[21], s 44 defines the jurisdiction of the Court. Absent a question of law, the appeal is incompetent. For this reason it is essential that an applicant identify what is in truth a question of law. A mixed question of fact and law is not a question of law within the meaning of s 44: Comcare v Etheridge (2006) 149 FCR 522 at [16]. 29 Furthermore, a finding of fact cannot be reviewed on appeal unless that finding is vitiated by an error of law: Waterford v Commonwealth (1987) 163 CLR 54 ("Waterford") at 77 (Brennan J). 30 In his amended notice of appeal, filed on 2 September 2014, P purported to identify seven questions of law: 1. In determining that both parents of Master A share care during the same period whilst Master A attends boarding school at St Josephs College has the Tribunal erred by disregarding s 54A(3) of the Act? 2. Did the Tribunal comply with its statutory duty under s 43(2) of the Administrate Appeal Tribunal Act by providing adequate reasons in relation to various findings made by it? 3. Did the Tribunal fail to afford procedural fairness to Mr P by refusing or failing to explain the approach that would be used to determine the percentage of care? 4. In determining whether the percentage of care determined by the Registrar under s 50(2) corresponds with the actual care of the child that the Registrar is satisfied the responsible person has had, is the parental responsibility granted under s 65DAC and s 65DAE in Division 2 of the Family Law Act 1975 of paramount consideration? 5. Did the Tribunal exceed its powers and thus commit a jurisdictional error by consciously departing from that Child Support Agency policies as they relate to: a) Consideration when a child is at boarding school? 6. Was there evidence or material before the Tribunal capable of supporting, or were there logical grounds capable of supporting, the following findings of fact made by the Tribunal: a) the consent orders were being complied with; b) that Ms M had daily contact with Master A; c) Mr P and Ms M were on an equal footing in respect of Master A's care whilst he was at boarding school? 7. Did the Tribunal exceed its powers and thus commit a jurisdictional error by consciously regarding (sic) evidence that Master A had chosen not to comply with the consent orders and ceased spending time with the second respondent? 31 With one qualification, these questions appear to be questions of law. The qualification relates to question 3. Different opinions have been expressed in this Court about whether a question of whether a party has been denied procedural fairness raises a question of law. The majority in Clements v Independent Indigenous Advisory Committee (2003) 131 FCR 28 (Gray ACJ and North J at [3]-[8]) considered that it did, but Gyles J at [66]-[67] did not, at least where the breach of procedural fairness did not appear on the face of documents provided by the tribunal to the Court under s 46 of the AAT Act. For my own part, I do not think it can be said that in every case where a denial of procedural fairness is alleged there will always be a question of law. Whereas the question of whether there is an entitlement to procedural fairness raises a question of law, it seems to me that whether a party has been denied procedural fairness is at best a mixed question of fact and law. Certainly, the question as framed by P meets this description. But the Registrar did not contend that any of these questions did not raise a question of law. In these circumstances, I propose to proceed on the basis that the appeal is properly constituted. 32 The grounds upon which the applicant alleged that the tribunal erred in law as set out in the amended notice of appeal were (without alteration): 1. [Section] 54A(3) of the Act requires that that neither parents can be caring for a child at the same time regardless of the method used in making a determination in the percentage of care under s 50(2). It is insufficient of the Tribunal to attribute to both parents during the same period and this has resulted in a legally faulted decision that is illogical. 2. It is illogical of the Tribunal to state that the time spent by Master A at St Joseph's is shared. By doing so the Tribunal has repeated the error made by the Tribunal in June 2012 as determined by the Judgement of Justice Buchanan dated 29 November 2012 which clearly outlined the legal principles to be applied. 3. It is irrational of the Tribunal in finding that the Second Respondent provides care during the time Master A spends at boarding school at the same level the Applicant. It unreasonable to place the Second Respondent and the Applicant on an equal footing in respect of Master A's care while he is at boarding school given the weight of evidence stating otherwise. 4. The Tribunal erred in the application of Polec & Staker & Anor (SSAT Appeal) [2011] FMCAfam 959 and Confidential and Social Security Appeals Tribunal [2010] AATA 892 to the facts. Thus making the decisions of the Tribunal dated 17 April 2014 irrational. 5. The conclusion that the consent orders dated 6 June 2011 are being complied with was not open to the Tribunal on the evidence thus making the finding of fact irrational. 6. The Tribunal failed to properly apply legal principle to shared parental responsibility and shared care. Thus making the decisions of the Tribunal dated 17 April 2014 illogical. 7. The Tribunal has failed to provided adequate reasons, or set out the reasoning process, in the finding that the second Respondent is responsible for 40% of the care of Master A while in attendance at St Joseph's College. 8. Although permissibly for the Tribunal to depart from legislation or policy, no compelling or proper reasons has been provided by Tribunal. By failing to give adequate reasons or set out the reasoning process when deciding to depart from legislation or policy the Tribunal has erred in law. 9. The Tribunal failed to give proper weight or consideration to the evidence provided to the Tribunal in witness testimony and written documents. Thus making the decision of the Tribunal dated 17 April 2014 irrational. 10. The Tribunal failed to give proper weight or consideration to the fact that the Applicant is solely responsible for Master A's school expenses which include school fees, accommodation, transport, meals, water, electricity, clothing, medical expense and extracurricular activities. Thus making the decision of the Tribunal dated 17 April 2014 both illogical and irrational. 11. By refusing to illuminate the Applicant with the alternative approach that was inevitably been used by the Tribunal to determine the percentage of care, despite his numerous requests. The Tribunal and Registrar have denied natural justice to the Applicant by failing to allow him to present his case on a level playing field and as such the ability to properly call evidence in reply. 33 Not all of these grounds will found an error of law. In Minister for Immigration and Multicultural Affairs v Al-Miahi (2001) 65 ALD 141; [2001] FCA 744 the Full Court (Sundberg, Emmett and Finkelstein JJ) said at [34]: [T]here is no error of law simply in making a wrong finding of fact. Even if the reasoning whereby the court reached its conclusion of fact were demonstrably unsound, that would not amount to an error of law. A party does not establish an error of law by showing that the decision-maker inferred the existence of a particular fact by a faulty process, for example by engaging in an illogical course of reasoning. Thus, at common law, want of logic is not synonymous with error of law. So long as the particular inference is reasonably open, even if that inference appears to have been drawn as a result of illogical reasoning, there is no place for judicial review because no error of law has taken place: Australian Broadcasting Tribunal v Bond (1990) 170 CLR 321 at 355-6; 21 ALD 1 at 23-4; 94 ALR 11 at 37-8. 34 In some circumstances, however, a decision reached by an irrational or illogical process of reasoning may demonstrate that an administrative decision-maker has erred in law: see, for example, Minister for Immigration v Li (2013) 249 CLR 332. On the other hand, describing a decision-maker's process of reasoning as irrational or illogical may just be an emphatic way of disagreeing with a finding of fact: Re Minister for Immigration and Multicultural Affairs; Ex parte Applicant S20/2002 (2003) 198 ALR 59; [2003] HCA 30 at [5] (Gleeson CJ). As Crennan and Bell JJ explained in Minister for Immigration and Citizenship v SZMDS (2010) 240 CLR 611 at [131]: If probative evidence can give rise to different processes of reasoning and if logical or rational or reasonable minds might differ in respect of the conclusions to be drawn from that evidence, a decision cannot be said by a reviewing court to be illogical or irrational or unreasonable, simply because one conclusion has been preferred to another possible conclusion.

Orders sought 35 In his amended notice of appeal P sought orders allowing the appeal, setting aside the tribunal's decision, substituting an order that the determination of the percentage of care for A be 77% to P and 23% to M, effective 8 January 2013 or, alternatively remitting the matter to the tribunal for determination according to law "within 30 days from the date of the judgement"; and a stay on all child support payments until the determination of the appeal. He also asked for an order for costs "payable within 21 days". The application for a stay was not actively pursued. While the written submissions mentioned the stay as one of the orders sought, P advanced no argument in support of a stay, either orally or in writing. Nor did he lay any foundation for it. Consequently, I made no such order.

Should P have leave to adduce further evidence? 36 On 1 August 2014 P filed an interlocutory application seeking leave to adduce further evidence on the appeal. The interlocutory application was listed for hearing on the day of the appeal. I heard argument about whether the further evidence should be admitted and as to its effect on the resolution of the issues in dispute if it were and indicated I would give my decision at the time I delivered judgment. 37 The application was supported by an affidavit sworn by P on 20 March 2014. In the affidavit P stated that the Registrar has made a 100% determination in his favour since the hearing before the tribunal and that the details of that determination were relevant to his appeal. He went on to say (in para 5) (without alteration): The evidence that was relied upon in this new determination was before Senior Member Redfern at the AAT hearing. It is my belief that it is illogically and irrational for the Child Support Registrar to reach totally disparate determination based on the same evidence. The transcript of the hearing before the AAT will show that the representative of the Child Support Registrar argued that the evidence should be disregard in the determination of Senior Member Redfern. 38 P said that he believed that the determination supported questions 2-7 inclusive and grounds 2-12 in his original notice of appeal. Most, but not all, of these questions and grounds correspond to questions and grounds in his amended notice of appeal. 39 The evidence in question is described in the interlocutory application as: Details of Objection Decision - STATEMENT OF REASONS dated 3 April 2014 prepared by the Child Support Registrar. 40 In fact, however, the evidence P sought to adduce related to a different decision made on 2 June 2014, which was a decision relating to P's objection to the 3 April decision. It was the statement of reasons for the 2 June 2014 decision which was annexed to P's affidavit. The earlier decision of 3 April 2014 was to the effect that for an interim period of 26 weeks from 8 January 2014 P had shared care for both C and A. On 2 June 2014 the Registrar allowed P's objection and substituted a new decision in relation to the interim period and a subsequent period as well. As the Registrar's decision in relation to the objection was made after the AAT had published its decision, and as the Registrar's decision record shows that there was evidence before the Registrar that was provided after the date of the AAT hearing, it is apparent that the assertion made in para 5 of the affidavit is false and must be rejected. 41 On an appeal from the AAT, the Court may receive further evidence for the purposes of making findings of fact under s 44(7) of the AAT Act (s 44(8)), not (as Brennan J observed in Waterford at [28]) for the purpose of demonstrating that the tribunal made an error or errors of fact: The error of law which an [applicant] must rely on to succeed must arise on the facts as the AAT has found them to be or it must vitiate the findings made or it must have led the AAT to omit to make a finding it was legally required to make. There is no error of law simply in making a wrong finding of fact. Therefore, an [applicant] cannot supplement the record by adducing fresh evidence merely in order to demonstrate an error of fact. 42 Section 44(7) provides that the Court may make findings of fact in an appeal if: (a) the findings of fact are not inconsistent with findings of fact made by the Tribunal (other than findings made by the Tribunal as the result of an error of law); and (b) it appears to the Court that it is convenient for the Court to make the findings of fact, having regard to: (i) the extent (if any) to which it is necessary for facts to be found; and (ii) the means by which those facts might be established; and (iii) the expeditious and efficient resolution of the whole of the matter to which the proceeding before the Tribunal relates; and (iv) the relative expense to the parties of the Court, rather than the Tribunal, making the findings of fact; and (v) the relative delay to the parties of the Court, rather than the Tribunal, making the findings of fact; and (vi) whether any of the parties considers that it is appropriate for the Court, rather than the Tribunal, to make the findings of fact; and (vii) such other matters (if any) as the Court considers relevant. (Emphasis added.) 43 Recently, in the same context Griffiths J referred to s 27 of the Federal Court of Australia Act 1976 (Cth) ("FCA Act") and r 33.29 of the Federal Court Rules 2011 (Cth), stating that under those provisions "the Court also has a discretion to admit fresh evidence on an appeal": Comcare v Martin [2015] FCA 4 at [59]. I respectfully disagree. 44 Section 27 of the FCA Act provides that the Court may receive further evidence on an appeal. But as s 27 is concerned with appeals in the appellate jurisdiction of the Court; it is to be found in Div 2 of Pt III of the Act, which is entitled "[a]ppellate and related jurisdiction (civil proceedings)". The appellate jurisdiction is defined in s 24. That definition does not include appeals from the AAT. Although this is an appeal, it is heard in the original jurisdiction of the Court. Accordingly, s 27 has no bearing on this application. 45 Rule 33.29 of the Federal Court Rules does relate to appeals from the AAT and appears in that part of the Rules which deals with matters in the original jurisdiction. Subrule 33.29(1) states that a party may apply for the Court to receive further evidence on appeal. The rest of the rule is concerned with the mechanics involved in the making of the application. In my respectful opinion, r 33.29 must be read with s 44 and is intended to apply in circumstances in which the AAT Act contemplates that further evidence could be received in an appeal. If there were any doubt about that, it seems to me that it is removed by the note to the rule, which reads: The Court may receive further evidence on an appeal for the purpose of making findings of fact under section 44(7) of the AAT Act. 46 Still, s 44(8) is not the sole source of power to admit further evidence in an AAT appeal. 47 Subsections (7) and (8) were added to s 44 by the Administrative Appeals Tribunal (Amendment) Act 2005 (Cth), which relevantly commenced on 16 May 2005. Before then, the Court had considered that further evidence could be admitted on an appeal, albeit in limited circumstances. In Committee of Direction of Fruit Marketing v Delegate of the Australian Postal Commission (1979) 37 FLR 457 at 458-9 Franki J (Brennan J agreeing at 483) said: In general a question of law arises after the determination of any necessary facts and the nature of the question of law usually depends upon the facts as determined … it seems that only in the most unusual circumstances, if at all, would this Court be justified in admitting fresh evidence. I take this view notwithstanding that the application to his Court, although loosely called an appeal, is an application in the original jurisdiction of the court. 48 In Rana v Repatriation Commission (2011) 126 ALD 1; [2011] FCAFC 124 at [20] the Full Court said that there was "a limited scope for the reception of further evidence" in a s 44 appeal "where that evidence tends to prove that the specified question of law should, for a reason given in a specified ground of appeal, be answered in a way that entitles or, as the case may be, disentitles an applicant to the orders sought". The Court went on to explain: The further evidence must, as the Full Court observed in Phillips's case [Phillips v Commissioner for Superannuation [2005] FCAFC 2], have a tendency, if admitted, to demonstrate an error of law. If, for example, the power of an administrative decision-maker or the tribunal sitting in place of that person was, on the true construction of the legislation conferring that power, only exercisable if a particular jurisdictional fact existed, further evidence which showed that the fact did or did not exist might be admitted on the hearing of a s 44 appeal in the exercise of a judicial discretion … In contrast, further evidence which touched on a matter of evaluative judgment on the factual merits of a claim would not be admissible, save perhaps exceptionally for the very limited purpose of underscoring why it was that, in the event that a question of law were answered as an applicant contended, a remitter of the matter to the tribunal for rehearing would not be an exercise in futility. 49 For the following reasons, the further evidence ought not be admitted in this appeal. 50 First, I am not satisfied that the Court can admit the evidence. P eschewed reliance on s 44(8). In other words he did not seek to adduce the evidence for the purpose of the Court making a finding of fact which was not inconsistent with the tribunal's factual findings. Nor did he seek to rely on it for any other legitimate purpose. Rather, as he put it in oral argument, his purpose was to demonstrate, through the Registrar's reasons in the later decision, that the Registrar's interpretation of the legislation in the earlier decision the subject of the application for review in the AAT was illogical or irrational. Yet the appeal is not concerned with the Registrar's interpretation of the legislation; it is concerned with the tribunal's interpretation. Inconsistencies in the position the Registrar may take from time to time have nothing to do with the issues on the appeal. In any case, it is always open to the Registrar to reconsider a determination. 51 Secondly, the premise for the belief expressed in para 5 of the affidavit is false. The evidence upon which the tribunal relied was not the same evidence as the evidence upon which the Registrar based the new determination. As I explain below (at [153]-[156]), the care period to which the tribunal decision relates is the period from 8 January 2013 until 7 January 2014. The Registrar, on the other hand, was dealing with the period from 8 January 2014. The decision the Registrar made on 2 June 2014 was based on the Registrar's factual finding (which in turn was based on the evidence provided by P) that as at 8 January 2014 the circumstances relating to the care of both A and C had changed. There could not be anything illogical or irrational about different decisions being made on the basis of different evidence about the state of affairs at different periods of time. 52 Thirdly, in these circumstances the evidence is irrelevant. It would not have affected the tribunal's decision.

Question 1: Was the tribunal bound to determine the percentage of care by reference to s 54A(3) of the Assessment Act? 53 P's primary contention (as outlined in ground 1 of the amended notice of appeal) was that s 54(3) was mandatory, regardless of the method used to determine the relative percentages of care. 54 In C's case both Wigney J and the Full Court decided this question against P. The Full Court held (at [43]) that s 54A(3) did not apply except in the context of an application of s 54A(1) or 54A(2). In substance, the very submissions P makes in the present case were made before, and rejected by, Wigney J with whom the Full Court agreed. 55 P made an attempt to distinguish C's case on two bases. 56 First, he argued that in C's case, the tribunal attributed the periods C spent at boarding school to either parent, whereas here they were attributed to both parents. 57 That is not so. The tribunal in C's case noted that it was agreed between the parties that when C was away from boarding school they shared his care equally and said that it was "appropriate … to regard C's care during the time he spends [at boarding school] as similarly shared equally by his parents": Confidential and Child Support Registrar [2013] AATA 426 at [44]. Indeed, on the appeal before Wigney J, P submitted that the tribunal erred by attributing care to both parents. 58 Secondly, P argued that the tribunal in this case found that he was paying A's school fees but in C's case the tribunal did not find that he was paying C's school fees. 59 As I have already mentioned, the tribunal in this case found that P's mother either paid the school fees or loaned money to P, at his request, to pay them. The tribunal in C's case made a similar factual finding, but (unlike the tribunal in the present case) was not satisfied that that meant that the level of care for the child was weighted in favour of P. Be that as it may, it has nothing to do with the point of law raised by question 1. 60 Thirdly, P suggested that the tribunal in the present case had in fact adopted the approach in either s 54A(1) or 54A(2) (it was not clear which, nor does it matter for present purposes) and was therefore bound to apply s 54A(3). 61 The suggestion must be rejected. It is patently not the case that the tribunal adopted the approach to assessment in s 54A(1) or (2). The senior member made it abundantly clear that she was adopting a different approach. 62 For present purposes, A's case is indistinguishable from C's. 63 In C's case, Wigney J held that: The use of the word "may" in subss 54A(1) and (2) indicated that it was a matter for the discretion of the decision-maker whether to use the number of nights to calculate the actual care of the child that the parents had or were likely to have during the care period. As a matter of statutory construction, a provision that uses "may" is prima facie permissive, not mandatory. In this respect his Honour referred to a number of authorities as well as s 33(2A) of the Acts Interpretation Act 1901 (Cth). There was no textual reason to displace the prima facie meaning. To the contrary, his Honour pointed out that s 54A(4) provides that the section does not limit s 50, 51, 52 or 54 and construing s 54A so as to impose an obligation on the decision-maker to determine the question in the way the section envisaged could be considered as a limitation. Nor was there any contextual reason to displace the prima facie meaning. Indeed, his Honour considered that the extrinsic material tended to confirm the prima facie meaning, referring to a passage in the Explanatory Memorandum to the Child Support and Family Assistance Legislation Amendment (Budget and Other Measures) Bill 2010 (Cth). He extracted the passage (at [2013] FCA 1312 at [61]), as did the Full Court (at [2014] FCAFC 98 at [39]). It is unnecessary for me to do so, too. It is sufficient to make two observations. First, the Explanatory Memorandum states that s 54A was merely intended as a guide and emphasises the warning contained in s 54A(4). Secondly, the Explanatory Memorandum also states that "if the number of nights in care does not appropriately reflect the actual care or extent of care the person has, then the Registrar may use a different method to determine the percentage care". If it is inappropriate in the particular circumstances of the case to use the methodology in s 54A, it is open to the Registrar to adopt a different approach. 64 His Honour observed at [63] that the position contemplated by the Explanatory Memorandum obtained in that case: That is plainly the position here. Where Master C was at boarding school he was not staying overnight with either parent. It is difficult to see how s 54A could provide any guidance or assistance in determining actual care in these circumstances. 65 And so it is here. 66 P submitted that it was an error of law to attribute the care of a child to more than one person at the same time, relying on s 54A(3) of the Assessment Act. 67 In C's case, however, the Full Court at [43] drew attention to the opening words of s 54A(3) - "[f]or the purposes of this section" - which self-evidently limit the operation of the subsection to cases in which the decision-maker opts to work out actual care on the basis of nights spent or likely to be spent in the care of one or other parent. The Court described this as "[a]n obvious difficulty with P's argument" and said that those prefatory words "make it very clear" that s 54A(3) does not apply except where s 54A(1) or (2) is invoked. 68 P also submitted that, in attributing care to both parents while A was at boarding school, the tribunal's decision disclosed the error of law exposed by Buchanan J in P v Child Support Registrar [2012] FCA 1398 ("the 2012 case") (at [30]), an earlier decision of this Court relating to C. But for the reasons given by the Full Court at [44], that judgment does not help P. In the 2012 case his Honour was hearing an appeal from a tribunal decision where the tribunal had applied s 54A. He actually queried, without deciding, whether it was in fact appropriate to apply s 54A to work out actual care in relation to the periods when C was at boarding school. As the Full Court observed at [44], his Honour did not say anything to suggest that any determination of percentage of care would necessarily have to have regard to the principle in s 54(3) that a child could not be in the care of more than one person at the same time. 69 I am in complete agreement with Wigney J and the Full Court. In any event, I am bound to follow the Full Court. Accordingly, and for the reasons given in that case, I find that the tribunal in the present case was not bound to determine the percentage of care by reference to s 54A(3). 70 Grounds 1 and 2 of the amended notice of appeal should therefore be dismissed.

Question 2: Did the tribunal breach its obligation under s 43(2) of the AAT Act to give reasons? 71 This question is said to engage grounds 4, 7 and 8. 72 P contends that the reasons given by the tribunal in this case were "wholly inadequate". He makes a number of complaints which I will shortly set out. 73 P submitted first, that, as appeals from AAT decisions lie only on questions of law, it is of fundamental importance that the reasons are expressed in such a way that "they are extremely obvious and so easy to understand that they are incontestable". In this case, he submitted, the reasons fell well short of this standard. 74 The submission, however, misstates the legal position. 75 Section 43(2) provides that subject to the section and to ss 35 and 36D, the AAT shall give reasons for its decision either orally or in writing. Where, as here, the reasons are given in writing, s 43(2B) provides that the reasons must include "its findings on material questions of fact and a reference to the evidence or other material on which those findings were based". 76 As Finkelstein J explained in Comcare Australia v Lees (1997) 151 ALR 647 at 656; [1997] FCA 1415: In determining whether the obligation to give reasons has been discharged a number of principles must be born in mind. First as Shepherd J said in Bisley Investment Corp Ltd v Australian Broadcasting Tribunal (1982) 40 ALR 233; 59 FLR 132 at 157 no standard of perfection is required in their preparation. What is required is that the reasons should be expressed in clear language so that they are capable of being understood: [Ansett Transport Industries (Operations) Pty Ltd v Wraith (1983) 48 ALR 500] at 507. The reasons need not deal with every detail of the evidence but must set out those parts of the evidence which are important for the conclusions arrived at: Our Town FM Pty Ltd v Australian Broadcasting Tribunal (No 1) (1987) 77 ALR 577. The reasons must disclose the reasoning processes of the tribunal: Telescourt v Commonwealth (1991) 29 FCR 227. Finally, in determining whether the reasons are adequate they must be considered fairly and not combed through "with a fine appellate toothcomb to find error": Minister for Immigration and Ethnic Affairs v Wu Shan Liang (1996) 185 CLR 259 at 291; 136 ALR 481; Broussard v Minister for Immigration, Local Government and Ethnic Affairs (1989) 98 ALR 180 at 187. (Emphasis added.) 77 The tribunal is not required to refer to every piece of evidence and every contention: cf. Applicant WAEE v Minister for Immigration and Multicultural and Indigenous Affairs (2003) 75 ALD 630; [2003] FCAFC 184 at [46] (French, Sackville and Hely JJ, in relation to the Refugee Review Tribunal). Nor is it required to make a finding on every question of fact which may be regarded as objectively material. As McHugh, Gummow and Hayne JJ explained in Minister for Immigration and Multicultural Affairs v Yusuf (2001) 206 CLR 323 at [68], where the legislation requires that the reasons include the findings on material questions of fact, the tribunal's obligation is to "set out its findings on those questions of fact which it considered to be material to the decision which it made and to the reasons it had for reaching that decision" (original emphasis). The focus of the subsection is on "the subjective thought processes of the decision-maker". 78 P's second submission does not address the question, which is concerned with the extent of the obligation to provide reasons. Rather, it focuses on the quality of the reasons. 79 P submitted that the tribunal's decision was "clearly based on the [Child Support Guide (Guide)] and [the judgment in] Polec v Staker [(2011) 253 FLR 339; [2011] FMCAfam 959]", (referring to [66] of the tribunal's reasons) when both the Guide and the judgment considered parental responsibility and decision-making to be "irrelevant" in determining the percentage of care. 80 This submission must also be rejected. It is not correct to assert that the decision was based on the Guide and the judgment in Polec. At [66] the tribunal stated only that it had assessed care "by reference to a range of factors consistent with the Guide and the decision in Polec" (emphasis added). In any event, neither the Guide nor the judgment states that parental responsibility and decision-making are irrelevant. On the contrary, in Ch 2.2.1 of the Guide, in a passage extracted by the tribunal at [18], the first question identified as relevant for the Registrar's consideration in any case where there is any doubt about whether or to what extent a person is caring for a child is: To what extent does the person have control of the child, including having overall responsibility for the child and making: • major decisions relating to who the child spends time with and the child's health, education, discipline, recreational and/or social activities; and • arrangements for others to meet the needs of the child. (Emphasis added.) 81 The tribunal also referred at [19] to another extract from the Guide in which the following statements appear: The percentage of care is the mechanism in the child support assessment formula takes into account the amount of time a parent or non-parent carer is responsible for providing care for the child. … Additionally, in limited circumstances, a person may have care of a child who is not living with them for a period of time. Example A person can provide care for a child who is at boarding school… … Consideration is given to who has responsibility for making arrangements for, and decisions about, the child's welfare, as well as who is meeting the child's costs … (Emphasis added.) 82 In Polec at [56] the federal magistrate listed six questions he considered it necessary to ask in order to determine whether and to what extent a person has care of a child: a) To what extent does the person meet the needs of the child by providing the child with accommodation, clothing, food, childcare, education, health care, emotional support, supervision, transport and extra curricular activities? b) To what extent does the person make arrangements for others to meet the needs of the child? c) To what extent does the person pay for the costs of meeting the needs of the child? d) To what extent does the person otherwise provide financial support for the child? e) To what extent does the child provide for his or her own needs or have those needs met from another source? f) To what extent is the child financially independent or financially supported from another source? 83 As Wigney J observed in C's case at [107], the list does not purport to be exhaustive. In any case, parental responsibility and decision-making are subsumed within the first two considerations in the list. 84 Thirdly, P submitted that "[t]he absence of detail on the specific factors and the percentage attributed to these factors" is a significant omission, "[preventing] a dissatisfied party from determining whether a reviewable error has been made" (cf. Ansett Transport Industries (Operations) Pty Ltd v Wraith (1983) 48 ALR 500 at 507; [1983] FCA 179). He referred to the finding at [82] in which the tribunal attributed 60% of the care to him and 40% to his wife for the periods during which A was boarding, submitting that the lack of detail surrounding the determination of the percentages prevented him from knowing whether there had been a miscalculation. 85 In substance, P's argument is the same argument he put to the Full Court in C's case, which the Court firmly rejected. At [97] of its reasons the Full Court said: We do not accept that this complaint is valid. There is no legal requirement to give more than adequate reasons. In any event, the AAT's reasons disclose that the percentage of care was determined on a pellucid basis that: a) P and M cared for C equally outside of school terms ([44] of the AAT reasons); b) P and M had shared parental responsibility for C during school terms ([22], [25], [26] of the AAT reasons); c) P and M were on an equal footing in most of the respects set out in the CSA guidelines and in Polec ([25] of the AAT reasons); d) The only apparent and potentially significant departure from that position is the payment of school fees ([25] of the AAT reasons); e) P did not pay the school fees ([40] and [41] of the AAT reasons); and f) It would be nonsensical to assess percentage care by reference to nights ([42] of the AAT reasons). 86 The only substantive difference between the tribunal's findings in C's case and those in the present case concerned the finding about payment of the child's school fees. In this case, the tribunal accepted that payment of fees was relevant to the question of care and should be given weight (at [78]), but observed at both [73] and [78] that it was only one relevant factor. The tribunal determined the percentage of care based on its findings that: (a) It was neither useful nor appropriate to attribute nights to either parent during the period that A was boarding and to do so in the circumstances of this case would be artificial and arbitrary ([67]); (b) The parents have shared parental responsibility for A ([70]); (c) They have largely followed the consent orders made on 6 June 2011 ([70]); (d) Both are involved with the school and provide emotional support to A while he is boarding ([71]); during this period M sees or speaks to A every day of the school week, is involved in parent-teacher meetings, and is listed as one of A's emergency contacts ([67]); (e) No major decisions about A's health care, medical treatment or education could be made during this period without reference to M ([67]); (f) From January 2013, P either paid A's school fees or caused them to be paid (at [79]); P's mother either paid, or "loaned" money to P to pay, those fees (at [75]); (g) The level of care for A when he is boarding was weighed in favour of P, but not significantly so. The percentage of care would have been equal but for the arrangement for the payment of school fees ([80]); (h) Outside of school terms either P or M was solely responsible for A's care and they shared custody equally ([83]); (i) Outside of school terms, the percentage of care for A was 50% each ([83]); and (j) When the percentages were combined (that is, during school terms and outside of school terms), P had actual care of A of 55% and M 45% ([83]). 87 I accept the Registrar's submission that the reasons are sufficiently clear to enable a person to identify not only the factors that the tribunal considered relevant to the assessment of each parent's percentage of care but also the weight that it attached to those factors. 88 The apportioning of percentages of care is not an exact science. No precise calculation is possible. In settling on the respective percentages during the periods when A was boarding, the tribunal explained at [82]: This takes into account that all A's expenses are paid during these periods, either by [P] or at his request, and [M] is not required to provide any financial support. It nonetheless also takes into account that [P] and [M] otherwise provide emotional support and ongoing responsibility for major decisions should they arise during the periods, in equal measure. It does not matter that no such major decisions have arisen for A during the period in question. The evidence is that if they had arisen, both [P] and [M] would have been involved in this decision-making process. 89 The Assessment Act does not require percentages to be assigned to individual components of care, as P's submission implied. 90 Fourthly, P referred to the remark in Polec at [45] that "[t]he most obvious matter to be considered in the circumstances of this case in which the child was living with neither parent was who is meeting the child's costs". He contended that the tribunal in the present case had "arrived at the diametrically opposed position in regard to the importance of Financial support" when it concluded that financial support was only one factor to be taken into account. There are two problems with this contention. It treats "obvious" as a synonym for "paramount", which it is not. And the underlying proposition that financial support is the paramount consideration in all cases was rejected in C's case: [2013] FCA 1312 at [108]; [2014] FCAFC 98 at [113]. 91 Fifthly, P submitted that the tribunal erred in law by failing to give adequate reasons or set out its reasoning process when deciding to depart from legislation or policy. 92 This submission must also be rejected. While the tribunal declined to work out actual care based on the approach in s 54A of the Assessment Act, the reason it declined to do so is pellucid. 93 P contended that Ch 2.2.1 of the Guide details how the percentage of care might be determined and (in effect), absent compelling reasons, should be followed by the tribunal. P claimed that the tribunal: deviated from the policy by not making a determination of the percentage of care for Master A, based on a section of the Guide only relevant for situations where a child is living under the same roof as both parents by siting the Decision of SM Bell. The example in this section of the Guide referred to by the Tribunal in the Decision clearly awards care to the parents at different times of the days in question and therefore adheres to the provision of s 54(3) as outlined by Justice Buchanan in P v Child Support Registrar [2012] FCA 1398. 94 This submission is incomprehensible. 95 P also complained that "[t]he salient section of the Guide" was not mentioned in the tribunal's reasons. This submission is entirely without foundation. The very passage P cites in support of it was extracted by the tribunal at [19] of its reasons. I referred to it above at [81]. 96 Sixthly, P submitted that the tribunal's decision was inconsistent with the decision in Confidential and Social Security Appeals Tribunal [2010] AATA 892, in which, he contended, it was decided (at [31]) that a parent cannot be "credited" with care if the child is attending boarding school and the parent is not contributing to the costs. He claimed that it was "unequivocally clear" from this decision that a parent who does not bear the cost of boarding school is not entitled to claim credit for care during the period the child is boarding and that this position was supported by what the tribunal did in C's case. 97 This submission must also be rejected. 98 The tribunal in Confidential and Social Security Appeals Tribunal did not decide that a parent cannot be credited with the care of a child at boarding school where the parent is not contributing to the fees. The passage P referred to at [31] says nothing to this effect. There, the tribunal said that the Guide notes that care is generally worked out on the basis of the number of nights and "[c]learly, in this case, where the child is at boarding school funded by neither parent, calculation of 'nights' becomes largely irrelevant". This observation provides no support for P's case, let alone the particular submission. 99 Furthermore, the submission misrepresents the tribunal's decision in C's case. The tribunal in C's case did not refrain from attributing care while the child was at boarding school, as P alleged. Rather, it found that responsibility for C's care was shared during these periods. This is entirely consistent with the decision in the present case. 100 Seventhly, P submitted that without explanation the tribunal failed to take into account "the irrefutable fact" that A has not been in the care of M since 16 December 2013. I deal with this submission below at [147] and following. For the reasons given there, this was not an appealable error. 101 P also submitted that the tribunal failed to provide "proper reasons" as to how A, "while living as a weekly boarder … could possibly be considered to be the same as a child living with their parents in the same house". This submission is based on a false premise. The tribunal did not treat A in this way or make any finding to this effect. 102 Finally, P complained about the tribunal's finding at [83] that either P or M was solely responsible for the care of A during periods when he was not attending boarding school. He submitted (without alteration): Based on the logical of [the tribunal] a parent with shared parental responsibility would always be providing a level of care and as such the parents of Master A could never be said to have sole responsibility has reasoned by [the tribunal] at paragraph [83]. 103 This is not a fair characterisation of the tribunal's reasons. There is no want of logic or inconsistency in the conclusion that, when the parents have shared custody, one or other parent is solely responsible for the care of A during periods when he was not at boarding school, as P insinuated. The tribunal's reference to sole responsibility was plainly concerned with what the tribunal referred to in C's case as "responsibilities for day-to-day decisions" and was not intended to exclude major decision-making or other aspects of "shared parental responsibility". The reasons must be read as a whole and in accordance with the principles in such cases as Collector of Customs v Pozzolanic Enterprises Pty Ltd (1993) 43 FCR 280 ("Pozzolanic") and Minister for Immigration and Ethnic Affairs v Wu Shan Liang (1996) 185 CLR 259 ("Wu Shan Liang"); that is to say, they must not "be construed minutely and finely with an eye keenly attuned to the perception of error" (Pozzolanic at 287, citing with approval Politis v Commissioner of Taxation (Cth) (1988) 16 ALD 707 at 708 (Lockhart J)). In a review of a tribunal decision for error of law, the Court is not concerned with looseness in the tribunal's language or unhappy phrasing of its thoughts: Pozzolanic at 287. Referring first to what the High Court said in Wu Shan Liang and second to an observation by the US Supreme Court in Edwards v California (1941) 314 US 160 at 186, McHugh J said in Minister for Immigration and Multicultural Affairs v Singh (2002) 209 CLR 533 at [56]: This Court has said "that the reasons of an administrative decision-maker are meant to inform and not to be scrutinised upon over-zealous judicial review by seeking to discern whether some inadequacy may be gleaned from the way in which the reasons are expressed". Unless that instruction is faithfully applied, the promise of judicial restraint in administrative review proceedings will be no more than "a promise to the ear to be broken to the hope, a teasing illusion like a munificent bequest in a pauper's will". (Citations omitted.) 104 I am not satisfied that the tribunal breached its obligation under s 43(2) of the AAT Act. The tribunal did not err as alleged in grounds 4, 7 and 8. To the extent that ground 8 is affected by Question 5, I address it below.

Question 3: Did the tribunal deny the applicant procedural fairness by failing to explain the approach that would be used to determine the percentage of care? 105 This question is said to relate to ground 11. 106 The submissions on this question repeated some of the matters canvassed in connection with question 2 and there is no need to traverse them again. Otherwise, the substance of P's complaint was that he was denied procedural fairness because he was not given advance notice of the approach the tribunal used to determine the percentage of care. He argued that the failure to do so deprived him of the ability to tender evidence and to make submissions about undisclosed factors to which the tribunal had regard. 107 It is indisputable that P was entitled to procedural fairness. But the complaint that he was not afforded procedural fairness must be rejected. 108 The tribunal considered that there were three possible options available to it to assess P's percentage of care for A: [2014] AATA 229 at [64]. It said that those options were the ones identified by the Registrar in his oral submissions and in his statement of facts, issues and contentions (the "Registrar's Statement"). The Registrar's Statement was filed and served on 2 January 2014, more than a month before the hearing. It was supplemented by additional particulars provided by the Registrar on 7 February 2014. With the exception of the allowance made for the payment by P or his mother with respect to the school fees, the approach taken by the tribunal was essentially the approach the Registrar urged in his Statement and the supplementary particulars, filed in advance of the hearing in the tribunal. It was the third of the options to which the tribunal referred at [30]. Procedural fairness is concerned with avoiding practical injustice: Re Minister for Immigration and Multicultural and Indigenous Affairs; ex parte Lam (2003) 214 CLR 1 at [37]. There was no practical injustice here. 109 Contrary to the suggestion implicit in P's submissions, procedural fairness does not require that the tribunal disclose what it is minded to decide or that it give a running commentary on what it thinks about the evidence: SZBEL v Minister for Immigration and Multicultural and Indigenous Affairs (2006) 228 CLR 152 at [48]. As the Full Court observed in Commissioner for Australian Capital Territory Revenue v Alphaone Pty Ltd (1994) 49 FCR 576 at 591: A person likely to be affected by an administrative decision to which requirements of procedural fairness apply can support his or her case by appropriate information but cannot complain if it is not accepted … Within the bounds of rationality a decision-maker is generally not obliged to invite comment on the evaluation of the subject's case … 110 The answer to question 3 is "no" and ground 11 should be dismissed.

Question 4: Is the parental responsibility under the Family Law Act 1975 (Cth) of paramount consideration? Did the tribunal fail to apply the correct legal principles? Were its findings therefore illogical and irrational? 111 P submitted that this question related to grounds 3 and 6. 112 P's opening submission on this question was that: [t]he Tribunal failed to properly apply the legal principles of shared parental responsibility and care. Thus making the Tribunal's decision illogical and findings irrational. 113 There is a non sequitur here. Even if the tribunal did fail to properly apply the principles in question, that would not necessarily render its decision illogical and its findings irrational. The two propositions should be considered separately. 114 The essence of P's argument was that the tribunal erred by conflating the concepts of "equal shared parental responsibility" (for which the consent orders made on 6 June 2011 provided) and "actual care". 115 As P submitted, the expression "shared parental responsibility" appears in the Family Law Act 1975 (Cth). "Parental responsibility" in relation to a child is defined in s 61B for the purposes of Pt VII of that Act to mean "all the duties, powers, responsibilities and authority which, by law, parents have in relation to children". It is not a definition, as P's submissions implied, for all purposes. 116 P contended that the legal definition of "shared parental responsibility" requires reference to s 65DAA of the Family Law Act and "to use s 65DAA without reference to s 61DA would clearly be unsafe, especially having regard to the notation with s 61DA". He then referred to s 61DA(1), which is in the following terms: 61DA Presumption of equal shared parental responsibility when making parenting orders (1) When making a parenting order in relation to a child, the court must apply a presumption that it is in the best interests of the child for the child's parents to have equal shared parental responsibility for the child. Note: The presumption provided for in this subsection is a presumption that relates solely to the allocation of parental responsibility for a child as defined in section 61B. It does not provide for a presumption about the amount of time the child spends with each of the parents (this issue is dealt with in section 65DAA). 117 It is difficult to see the relevance of s 61DA. The tribunal did not "use s 65DAA", as P contended, and the tribunal was not making a parenting order. 118 P referred to various other sections of the Family Law Act: s 65DAA ("Court to consider child spending equal time or substantial and significant time with each parent in certain circumstances"), s 65DAC ("Effect of parenting order that provides for shared parental responsibility") and s 65DAE ("No need to consult on issues that are not major long-term issues"). 119 These provisions are only relevant to explain the background to the consent orders. They do not bear upon the meaning or application of the relevant provisions of the Assessment Act. 120 P argued that the tribunal appears to suggest that, in this case, where the parents have been granted "equal shared parental responsibility", "this must be equated with 'actual care'", a proposition which, P argued, was both legally unsound and not supported by either statute or case law. But the tribunal suggested no such thing. To the contrary, at [70] the senior member said that she accepted that shared parental responsibility does not necessarily equate to shared care. Her point was that the fact that the parents had largely followed the consent orders was relevant when determining actual care. There is nothing in the Assessment Act that expressly precludes such a consideration. Nor is there anything in the subject-matter, scope or purpose of the Act to imply that it is a consideration which is to be disregarded. P referred to no authority to support his argument that the tribunal's approach was contrary to the case law. 121 The weight to be attached to this consideration was a matter for the tribunal. 122 The tribunal's approach was not legally unsound, nor was its decision illogical or its findings irrational. 123 P criticised the Registrar for being inconsistent in his approach to the determination of actual care, comparing a submission made to the tribunal by Mr Gouliaditis, who was then appearing for the Registrar, with a submission made by another advocate on a previous occasion in a different case (involving C). It is not at all clear that the positions of the two advocates were inconsistent. But even if they were, that is beside the point. The question for this Court is whether the tribunal in the present case erred in law in the manner alleged, not whether the Registrar's approach was inconsistent with its approach in an earlier case. I have concluded that the answer is that it did not.

Question 5: Did the tribunal exceed its powers by consciously departing from the Child Support Agency's policies as they relate to considering when a child is at boarding school? 124 This question is said to relate to grounds 8 and 10. 125 P submitted that the tribunal consciously departed from the Guide when, in the absence of compelling reasons, the tribunal was not allowed to. In this regard he relied on the observation made by Buchanan J in the 2012 case. There, at [3], after referring to the Guide, his Honour said: [S]uch guides are not binding, but they are generally applied unless there are compelling reasons not to do so… 126 P freely admitted that the submission that the tribunal has departed from the Guide was based entirely on speculation. He claimed to have been driven to this position by the lack of adequate reasons. He suggested that the tribunal must have determined the percentage of care for A, based on a section of the Guide which is only relevant to situations where a child is living under the same roof as both parents and not the section dealing with children attending boarding school. 127 This very argument was put in C's case and at [80]-[92] of its judgment the Full Court rejected it. Regardless of whether there was a departure from the Guide, as the Full Court held at [89]-[91], P's proposition (that, as a matter of law, unless there were compelling reasons not to, the tribunal was bound to follow it) is unsound. The tribunal was not required to comply with the Guide or precluded from departing from it except for compelling reasons. As it was in C's case, so it is here. Subject to the question of procedural fairness, which I have already dealt with, any departure from or misapplication of the Guide is not sufficient to demonstrate that the tribunal exceeded its powers and fell into jurisdictional error. The Full Court referred at [89] to the remarks of Bowen CJ and Deane J in Drake v Minister for Immigration and Ethnic Affairs (1979) 24 ALR 577 ("Drake") at 590-1. They bear repeating here. It is not desirable to attempt to frame any general statement of the precise part which government policy should ordinarily play in the determinations of the Tribunal. That is a matter for the Tribunal itself to determine in the context of the particular case and in the light of the need for compromise, in the interests of good government, between, on the one hand, the desirability of consistency in the treatment of citizens under the law and, on the other hand, the ideal of justice in the individual case. 128 P also sought to support his argument by relying on the decision of the Registrar that P has 100% care of A and C, made on 2 June 2014. He argued that the two decisions are inconsistent and it necessarily follows that the tribunal must have committed jurisdictional error. Yet, merely because the Registrar reached a different conclusion in June 2014 does not mean that the earlier conclusion was legally erroneous. Questions of legal unreasonableness aside, there is no error of law in making a wrong finding of fact. Brennan J explained the position in Attorney-General for the State of New South Wales v Quin (1990) 170 CLR 1 at 35-6: The duty and jurisdiction of the court to review administrative action do not go beyond the declaration and enforcing of the law which determines the limits and governs the exercise of the repository's power. If, in so doing, the court avoids administrative injustice or error, so be it; but the court has no jurisdiction simply to cure administrative injustice or error. The merits of administrative action, to the extent that they can be distinguished from legality, are for the repository of the relevant power and, subject to political control, for the repository alone. 129 In any case, as the Registrar points out, there was no departure from the Guide. 130 The Guide states, for example, that where there is doubt about the extent to which a person is caring for a child: the Registrar will consider whichever of the following are relevant to the particular case. • To what extent does the person have control of the child, including having overall responsibility for the child and making: o major decisions relating to who the child spends time with and the child's health, education, discipline, recreational and/or social activities; and o arrangements for others to meet the needs of the child. • To what extent does the person meet the needs of the child by providing the child with accommodation, clothing, food, child care, education, health care, emotional support, supervision, transport and extra curricular activities? • To what extent does the person pay for the costs of meeting the needs of the child? • To what extent does the person otherwise provide financial support for the child? • To what extent does the child provide for his or her own needs or have those needs met from another source? • To what extent is the child financially independent or financially supported from another source? 131 Under the heading "Percentage of Care", the Guide relevantly states: The percentage of care is the mechanism in the child support assessment formula takes into account the amount of time a parent or non-parent carer is responsible for providing care for the child. A parent or non-parent carer's percentage of care for a day in a child support period is the percentage of care that the person is likely to have of the child during the care period. Care will generally be worked out based on the number of nights that the child is likely to be in the care of the person during the care period (section 48(2) of the unamended Act, section 54A of the amended Act). … From 1 July 2010, the Registrar can base the care determination on hours of care over the care period if a determination based on nights would be inappropriate … Additionally, in limited circumstances, a person may have care of a child who is not living with them for a period of time. Example A person can provide care for a child who is at boarding school, in hospital or in separate accommodation… Consideration is given to who has responsibility for making arrangements for, and decisions about, the child's welfare, as well is who is meeting the child's costs, rather than just the accommodation arrangements themselves. The Registrar will give weight to statements from both parents and any non-parent carers. (Emphasis added.) 132 The tribunal did not err in the manner contended in grounds 8 and 10. To the extent that ground 10 is affected by Question 6, it is addressed below.

Question 6: Was there evidence or material before the tribunal or logical grounds capable of supporting the findings that:

(c) that P and M were on an equal footing in respect of A's care whilst he was at boarding school? 133 This question relates to grounds 5 and 10. 134 P submitted that the tribunal "failed to give proper weight or consideration to the evidence", that the consent orders were not being complied with and that A had not lived with M since 16 December 2013. Indeed, P submitted that there was no evidence that M had daily contact with A. He suggests that the tribunal confused his own evidence with that of his ex-wife. For this reason, P contends, the tribunal's finding is irrational. 135 These submissions must be rejected. 136 First, the tribunal did not find that the consent orders were being complied with. 137 The tribunal's finding was that P and M had "largely followed the consent orders" (at [70], emphasis added). There was evidence from M of non-compliance since 8 January 2014 but, as I explain below, because of the care period the tribunal had identified, this evidence was irrelevant. The evidence to which the tribunal referred at [48]-[52], [59]-[62] and [70]-[72] supports this finding. Ground 5 must therefore be dismissed. 138 With respect to the second matter, the tribunal stated at [67] that M "sees or speaks to A everyday during the week while he is at school". P submitted that this was his evidence, not M's. 139 It is true that P gave evidence to this effect. He was asked what contact he had with A while he was at school. He replied: I speak to him every day via phone. I attend most nights, I'd go up and see him most nights… 140 But, as the Registrar submitted, M gave evidence to the same effect in relation to her care of A, both in her statement of facts, issues and contentions ("M's Statement") and in her evidence in chief. The tribunal referred to M's Statement at [60] of its reasons and the oral evidence at [61]. 141 At [60] the tribunal said: [M] filed a statement of facts issues and contentions in which she stated the following: I provide care for [A] in all the usual ways when he is living with me, including providing food, clothing, extra curricular and leisure activities. I continue to provide care for [A] during the times he is at boarding school: • I am listed by the school as a parent who would be contacting case of ill-health or emergency. • I am involved with the school and with decision-making regarding [A]. • I have regular contact with [A] by telephone while he is at school; • I meet [A] or (sic) lunch regularly during school terms and makes (sic) purchases of food, toiletries and other items while he is at school; • I transport him to and from school on the weekends he spends with me; • I maintain accommodation, at significant costs, near to the school and I keep my home equipped with clothing and equipment for [A] and the other two boys. 142 At [61] the tribunal said: [I]n her view, leaving aside payment of the school fees and expenses, there was "zero" difference between her contribution and the contribution of the applicant to the care for A". 143 This was an accurate account of what M said in her oral evidence. 144 There was other material before the tribunal along the same lines. For example, there was an email from M to the Registrar dated 5 June 2013 in which she advised (without alteration): This is to state that the care of percentage should remain at 50% per parent. The court orders provide care to be shared and that has not changed. Both [P] and myself share the cost of all children in extra curricular activities as well as medical and both of us provide emotional support … [P] … spends the same amount of time will all three children as myself. I have provided [A] and [C] with casual clothes that they wear whilst at school. I also will visit them regularly and when I do, I take them snack's and toiletries. I have also supplied them both with their own pillow, pillow case, doona cover and doona, which I wash when they are with me and send it back clean… 145 The tribunal accepted the evidence of both P and M on the pattern of care from January 2013 to the time of the new application for variation made on 8 January 2014. For the reasons given below what happened after 7 January 2014 was not relevant to the determination of care in this case and ground 10 should also be dismissed.

Question 7: Did the tribunal fall into jurisdictional error by consciously disregarding evidence that A had decided not to live with his mother? 146 This is the issue raised by ground 9 but, as I have indicated, also bears on ground 10. 147 P contended that the tribunal ignored "irrefutable evidence" that since 16 December 2013 A decided to live exclusively with his father and that it provided no explanation as to why the evidence was not considered. 148 It is not in dispute that uncontradicted evidence was given at the hearing in the tribunal that A had left his mother's home on 16 December 2013. P testified that A had been living with him ever since and that on 8 January 2014, when he was due to return to his mother, he did not do so. M admitted that A did not return to her, though not that he remained with P. 149 The tribunal did not specifically refer to this evidence in its reasons. In his written submissions the Registrar submitted that the failure to refer to the evidence in the reasons did not necessarily mean that the evidence had been overlooked. After all, s 43(2B) of the AAT Act requires the tribunal to include in its reasons findings on "material questions of fact" and the evidence or other material on which those findings were based. It was for the AAT to decide what evidence or other material was relevant and to give it the weight it considered appropriate. The Registrar invited the Court to infer "from the totality of the evidence and the transcript of proceedings before the AAT" that this evidence was not considered significant. 150 It is true that a failure to refer to evidence in the reasons does not necessarily mean that the evidence has been overlooked (SZDXZ v Minister for Immigration and Citizenship [2008] FCAFC 109 at [22]-[32]). In this case the evidence that A was not living with his mother in the period from 13 December to 7 January was consistent with the consent orders. In this respect, it is likely that the tribunal did not consider the evidence to be significant. In relation to the period thereafter, the compelling inference is that the tribunal considered the evidence to be irrelevant. 151 I referred above to s 50 of the Assessment Act, which was the power the tribunal was exercising (standing in the shoes, so to speak, of the Registrar). It is convenient at this point to set out its terms in full: 50 Determination of percentage of care - responsible person has had etc. a pattern of care for a child (1) This section applies if: (a) either of the following applies: (i) an application is made under section 25 or 25A for a parent to be assessed in respect of the costs of the child; (ii) a parent is taken under section 73A to have had a relevant dependent child from a day specified in that section; and the Registrar is satisfied that a responsible person for the child has had, or is likely to have, a pattern of care for the child during such period (the care period) as the Registrar considers to be appropriate having regard to all the circumstances; or (b) the Registrar: (i) revokes, under Subdivision C of this Division, a determination of a responsible person's percentage of a care for a child that was made under section 49 or this section; and (ii) is satisfied that the responsible person has had, or is likely to have, a pattern of care for the child during such period (the care period) as the Registrar considers to be appropriate having regard to all the circumstances. (2) The Registrar must determine the responsible person's percentage of care for the child during the care period. (3) The percentage determined under subsection (2) must be a percentage that corresponds with the actual care of the child that the Registrar is satisfied that the responsible person has had, or is likely to have, during the care period. (4) Subsection (3) does not apply if section 51 or 52 applies in relation to the responsible person. (Original emphasis.) 152 It can be seen that "care period" is defined in s 50(1) as the period: (a) during which the Registrar is satisfied that a responsible person for the child has had, or is likely to have, a pattern of care for the child; and (b) which the Registrar considers to be appropriate having regard to all the circumstances. 153 In this case the tribunal defined the care period to be from 8 January 2013 to 7 January 2014, as it indicated to the parties during the hearing and as it stated in its reasons (at [62]). Those reasons make it clear that the care arrangements from 13 December 2013 until 7 January 2014 were not significant because they were consistent with the consent orders and that thereafter the evidence was irrelevant. 154 At [62] of her reasons the senior member said: I accept the evidence of both [P] and [M] on the key issues in dispute in these proceedings, which are about the pattern of care of A from January 2013 to the time of the new application for variation made in January 2014. There was acrimony between [P] and [M] about a number of issues and this was evident during examination and cross examination. Both raised matters that were not germane to the issues before me and on occasion [P] was evasive and not responsive or combative in responding to questions. In particular he was sensitive about answering questions on his finances and both he and [M] sought to raise issues about the contentious custody dispute that had emerged in the weeks prior to the hearing. Notwithstanding these distractions, their evidence was to the effect that, even though there have been disputes about custody and care and compliance with the orders, the care arrangements for the past year until January 2014 have generally been in accordance with the consent orders. (Emphasis added.) 155 She then proceeded to calculate the percentages of care based on the pattern that had obtained during the twelve month period from 8 January 2013, being the date from which P had sought a revocation of the existing determination, until 7 January 2014, being the day before the date of P's new application. This was not a jurisdictional error. Section 43(1) of the AAT Act gave the tribunal the power conferred on the Registrar by s 50(1)(a) of the Assessment Act to determine the outer limits of the care period to which the decision would relate. P contended in oral argument that to limit the care period in this way was a breach of s 54B of the Assessment Act. He did not explain why and the argument was never developed.

Conclusion 156 None of the grounds of appeal is made out. It follows that the appeal must be dismissed with costs. There will be orders accordingly. I certify that the preceding one hundred and fifty-six (156) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Katzmann.