For some time, it had been thought that the argument that it was unreasonable for the IAA to fail to exercise its power in s 473DC to obtain new information if the IAA was proposing to make a different and adverse conclusion to that of the delegate was limited to where the delegate did not consider relocation (or a particular place of relocation) and the IAA affirmed the refusal based on relocation (or to a different place of relocation).
This has been confirmed as wrong.
In DPI17 v Minister for Home Affairs  FCAFC 43, the IAA rejected the applicant’s claim to have been sexually abused, even though the delegate accepted the claim. The IAA did not put to the applicant that it intended to reach a different finding, and seek new information. Griffiths and Steward JJ said at -:
It is appropriate to say something more about DGZ16 and the Minister’s strong reliance upon it. In particular, the Minister pointed to what the Full Court said in DGZ16 at  (which is set out in  above). That passage should be read in the context of the particular facts and circumstances of that case. As the Full Court had earlier emphasised at , that was not a case where the IAA had decided a point which was not the point decided by the delegate. Instead, as is made clear at , the Full Court was responding there to a contention made by the appellant there that, merely because the IAA had before it the appellant’s submissions and had accepted the new information in those submissions, the IAA was obliged, whether as a matter of legal reasonableness or otherwise, to invite the appellant to respond once the IAA formed specific reservations about the appellant’s case. It was in this context, and with particular reference to the circumstances of that case, that the Full Court stated at  that it was open to the IAA to disagree with the delegate’s evaluation of the material without providing the appellant with an opportunity to respond.
These statements by the Full Court should not be viewed as establishing a general principle that the IAA is never obliged to provide the appellant with an opportunity to respond if the IAA disagrees with the delegate’s evaluation of material.
It is significant that the Full Court in DGZ16 viewed the case there as being different from that in CRY16 (where the IAA affirmed the delegate’s decision to refuse the SHEV but on a different basis of reallocation which had not been addressed by the delegate). In DGZ16, their Honours expressly stated at  that in DGZ16 that “there may be circumstances in which it is legally unreasonable not to consider the exercise of the discretionary power in s 473DC(3)”. This statement serves to underline the central importance of paying close attention to the particular facts and circumstances in which the issue of legal unreasonableness is raised.
Mortimer J’s also reasons set out the particular facts and importance of being able to observe demeanour in cases where sexual abuse are claimed (the IAA did not have the benefit of observing the applicant in the interview). However, her Honour’s reasons do not suggest that unreasonableness is limited to this kind of fact scenario, and the applicability of DPI17 is not confined in this way.