“Exceptional circumstances” a matter of law?

The AAT wrote as follows:

It is in the interests of both the Minister and the public that action to challenge decisions is taken within a reasonable time. I am satisfied that both the Minister and the public would expect timelines to be adhered to in a matter like the present. There is prejudice to the public and the general administration of justice if decisions are not regarded as final and can be re-opened after a period of 12 years unless there are truly exceptional circumstances, which do not present in this case even accepting the difficulties the Applicant faced.

The questions to the Federal Court (FCA) were as follows:

Question 1: As a matter of law, do applicants who apply for time extension under s 29(7) of the AAT Act need to establish “truly exceptional circumstances”?

Question 2: In determining whether to extend the time for making a merits review application, was the correct approach for the Tribunal to weigh up the relevant factors referred to in Hunter Valley Developments and summarised in ActewAGL Distribution v Australian Energy Regulator (2011) 195 FCR 142 at [88]?

Question 3: Did the AAT treat the need for exceptional circumstances as a matter of law?

Question 4: Is it "common sense that the longer the delay the more difficult it will be for an applicant to persuade any tribunal that an extension of time should be granted?

Question 5: Is it "a matter of common sense that the longer the delay the better the explanation will need to be"?

The FCA answered those questions as follows: