The proposition to the contrary, that there is a requirement for illogicality or irrationality to also be ‘extreme’, is made by the Minister with alarming frequency and betrays an understanding of what exactly is required to make out a jurisdictional error of this kind.
In AWU16 v Minister for Immigration and Border Protection  FCA 513 the Federal Court said:
 Referring to CQG15 v Minister for Immigration & Border Protection  FCAFC 146; 253 FCR 496 at , the Minister submitted that the alleged illogicality or irrationality of reasoning must be of an “extreme” kind, not a matter on which reasonable minds might differ, and not a matter on which a supervising Court simply disagrees with a decision-maker, even emphatically.
 Save for the gloss arising from the word “extreme”, those propositions can also be accepted and are well established. There is nothing in High Court authorities such as Minister for Immigration and Citizenship v SZMDS  HCA 16; 240 CLR 611 which suggests that the adjectival description of “extreme” is a necessary element in a finding of illogicality or irrationality. If the decision-maker’s fact finding is proven to be irrational or illogical, in a way which was material to the outcome of the review, that is sufficient. The stringency of the threshold arises in the need for the decision-maker’s reasoning to be capable, objectively, of being described as irrational or illogical.