In proceedings such as this, reasons for a decision given by an administrative decision maker such as the assessor are not to be scrutinised by “over-zealous judicial review by seeking to discern whether some inadequacy may be gleaned from the way in which the reason are expressed” (see Minister for Immigration & Ethnic Affairs v Wu Shan Liang  HCA 6 ; (1996) 185 CLR 259 at ).
 Further, s 69 of the Supreme Court Act does not empower the Court to review an assessor’s decision for error of fact. Such a review is confined, in the case of an error of law that appears on the face of the record of the proceedings, to the reasons expressed by the assessor for the certificate issued and the certificate itself (see s 69(4)). The Court may also review the decision for jurisdictional error (see Craig v South Australia  HCA 58 ; (1995) 184 CLR 163).
 In Australian Broadcasting Tribunal v Bond  HCA 33 ; (1990) 170 CLR 321 Mason CJ explained at – that ordinarily, a finding of fact, including an inference drawn from primary facts, will not constitute a reviewable decision. If, however, a statute requires or authorizes the decision-maker to determine an issue of fact as an essential preliminary to the taking of ultimate action or the making of an ultimate order, then the determination of that issue of fact is reviewable. An ultimate determination which depends upon a finding of fact which is vitiated by error of law, or made without evidence, is also reviewable.
 Further, while there is no error of law simply in making a wrong finding of fact, whether there is any evidence of a particular fact is a question of law, as is the question of whether a particular inference can be drawn from facts found or agreed (see at –). Making findings and drawing inferences in the absence of evidence, also involves an error of law.
 As discussed in QBE Insurance (Australia) Ltd v Miller  NSWCA 442 at , review proceedings are thus:
… limited to determining whether the proper officer’s opinion has been properly formed according to law: Buck v Bavone  HCA 24 ; 135 CLR 110; at 118–119 (Gibbs J); D’Amore at . The critical question is thus “whether the determination was irrational, illogical and not based on findings or inferences of fact supported by logical grounds”: Minister for Immigration and Multicultural and Indigenous Affairs v SGLB HCA 32; 78 ALJR 992 at  (Gummow and Hayne JJ). Further, as explained by Latham CJ in The Queen v Connell; Ex parte Hetton Bellbird Collieries Ltd  HCA 42 ; 69 CLR 407 at 432:
If the opinion which was in fact formed was reached by taking into account irrelevant considerations or by otherwise misconstruing the terms of the relevant legislation, then it must be held that the opinion required has not been formed. In that event the basis for the exercise of power is absent, just as if it were shown that the opinion was arbitrary, capricious, irrational, or not bona fide.
 Failing to take into account a “relevant consideration”, that is, a factor which, by law the decision-maker is bound to take into account, also involves jurisdictional error (see Minister for Aboriginal Affairs v Peko-Wallsend Ltd  HCA 40 ; (1986) 162 CLR 24 at 39; Allianz Australia Insurance Ltd v Cervantes  NSWCA 244 ; 61 MVR 443). A constructive failure to exercise jurisdiction may also arise because the statutory conferral of power has not been exercised, according to its terms (see Cervantes at ).
 The reasons given for an assessment under the Motor Accidents Compensation Act have to be directed to what is in issue between the parties. As explained in Insurance Australia Limited trading as NRMA Insurance v Helou  NSWCA 240 at , such reasons must identify the various heads of damage awarded and explain how the numbers attributed to each of those heads of damage have been arrived at.
 Further, to fail to respond to a substantial, clearly articulated argument relying upon established facts, can involve a denial of natural justice (see Dranichnikov v Minister for Immigration and Multicultural Affairs  HCA 26 ; (2003) 77 ALJR 1088 at .) A failure to accord procedural fairness can also involve jurisdictional error (see Kirk v Industrial Court of New South Wales  HCA 1 ; (2010) 239 CLR 531 at  and Re Refugee Review Tribunal; Ex parte HB  HCA 34 ; (2001) 179 ALR 513 at .)
 What the law is concerned with, both in the case of questions of procedural fairness and natural justice, is to avoid practical injustice (see Re Minister for Immigration and Multicultural and Indigenous Affairs; Ex parte Lam  HCA 6 ; (2003) 214 CLR 1 at  per Gleeson CJ).
 It follows that in order to resolve the various issues lying between the parties on this application, it is necessary to consider not only the assessor’s reasons for the disputed conclusions which he reached, but also to consider the cases which the parties had advanced at the hearing and the evidence which they then led.