Ground 1 of the appeal: the birth certificate
57 The primary judge's reasons set out in detail the legislative scheme under the Births, Deaths and Marriages Registration Act, and also the Status of Children Act. I consider there were two main points his Honour drew from the legislative schemes:
(a) Both pieces of legislation, principally the Births, Deaths and Marriages Registration Act, gave a birth certificate issued in accordance with the Births, Deaths and Marriages Registration Act a prima facie probative value. The primary judge contrasted this with the delegate's finding that "the birth certificate in itself is not evidence of parentage" at p 7 of the delegate's reasons.
(b) The statutory obligation in s 15 of the Births, Deaths and Marriages Registration Act, imposed on the parents of a child, to have a birth registered. Section 15(1) provides:
The parents of a child are jointly responsible for having the child's birth registered under this Act and must both sign the birth registration statement but the Registrar may accept a birth registration statement from one of the parents if satisfied that it is not practicable to obtain the signatures of both parents on the birth registration statement.
58 As the Minister's submissions recognise, the primary judge was not finding that the delegate was "bound" by the terms of the Victorian legislation. The primary judge was explaining why the delegate's finding that "the birth certificate in itself is not evidence of parentage" involved a legal error. The primary judge was clearly correct that the delegate's conclusion did involve a legal error. The delegate's finding is inconsistent with the law as declared in both the Births, Deaths and Marriages Registration Act and the Status of Children Act.
59 It was the delegate himself who used the word "evidence", and that is why the primary judge fastened on it, in my opinion correctly. Where there is a statutory obligation to give reasons, the way an administrative decision-maker expresses their findings demonstrates what they considered important or material, and what they did not: Minister for Immigration and Multicultural Affairs v Yusuf [2001] HCA 30; 206 CLR 323 at [69]; quoted with approval in Minister for Immigration and Border Protection v SZMTA [2019] HCA 3; 264 CLR 421 at [14] (Bell, Gageler and Keane JJ); [106] (Nettle and Gordon JJ). The way the delegate expressed himself indicates that what is meant by giving the birth certificate "little weight", having found it is "not evidence" of parentage, is to render it insignificant to the formation of the delegate's state of satisfaction.
60 As the primary judge observed in his Honour's reasons at [34], that approach is inconsistent with the legal effect of a birth certificate. That the document is given that legal effect by State legislation reflects no more than the division of legislative power under the Constitution, and does not detract from the position that the certificate is given a legal effect. That was what the delegate failed to understand. As the Full Court said in Chou at [114], this is a legal error affecting the validity of the decision, referring there to Graham v Minister for Immigration and Border Protection [2017] HCA 33; 263 CLR 1 at [68] per Kiefel CJ, Bell, Gageler, Keane, Nettle and Gordon JJ.
61 While the Minister seeks to diminish the significance of the delegate's finding by linking it to other findings about "self-declared" information, I have explained why that makes the gravity of the error greater.
62 The primary judge was also correct to focus on the obligation imposed by s 15 of the Births, Deaths and Marriages Registration Act, read with the terms of s 16(1) which provide that the identity of a child's parent can only be included if the parents make a joint application for that inclusion. Again, as his Honour recognised, the joint parental responsibility for applying for a birth certificate, and the circumstances in which a person's identity may be entered as a parent, were critical factors in the task under s 37. While it is unclear whether the parties referred the primary judge to the decision in H, or placed much emphasis on it, the ASRC certainly did in its submissions to the delegate. The primary judge's references to s 15 and s 16 of the Births, Deaths and Marriages Registration Act, far from being erroneous, are compatible with the importance of self-identification as a parent, being a critical aspect of the decision in H.
63 Ground 1 fails. To the extent it is necessary to determine "materiality", not in relation to jurisdictional error, but in relation to the AD(JR) Act, being the jurisdiction invoked to review the delegate's decision, I consider it is plain that the delegate's misunderstanding that a birth certificate is "not evidence" of parentage "contributed" to the outcome of the decision, and the delegate's decision may well have been different if he had correctly understood the legal effect of a birth certificate: see Australian Broadcasting Tribunal v Bond [1990] HCA 33; 170 CLR 321 at 353 (Mason CJ), 365 (Brennan J), 369 (Deane J), 384 (Toohey and Gaudron JJ); Riseley v Suncorp Portfolio Services Ltd [2022] FCAFC 8; 290 FCR 75 at [87]-[88]. The birth certificate was a critical government record, material to Ms Nguyen's application, and rightly so given the legal effect it has, and given the acknowledgment of parentage that it represents.
64 That conclusion is sufficient to dismiss the appeal, but since the other grounds of appeal were fully argued, I have decided them.