Courts are generally very cautious about finding that relief in judicial review cases would be futile.
It is common in judicial review proceedings for the respondent to claim that an error made no difference to the outcome, and that relief to the applicant should therefore be denied. In House v Defence Force Retirement and Death Benefits Authority  FCAFC 72, the Full Federal Court confirmed that the test is not easy for a respondent to satisfy.
The error, the decision, and whether it mattered
House concerned a decision of the Administrative Appeals Tribunal which both the applicant and the respondent agreed was tainted by error. However, the respondent argued that the error "would not have affected the result" and therefore that the decision of the AAT should stand.
The Court said that the test was not whether the error "would" have made a difference, but whether the error "could make no difference". To put it another way, "relief will not be refused in the face of demonstrated error unless there is no possibility of a successful outcome."
The decision in House was finely balanced; there appeared to be a relatively good argument that the Tribunal had considered all the material (notwithstanding the error of law) and that the error committed would not have affected the outcome. However, the Court was cautious and held that:
"When the question involves the exercise of a discretion and the error of law is relevant to the framework within or foundation upon which the facts are to be determined and upon which the discretion is exercised, the Court ought to exercise great caution before deciding that the error of law could make no difference to the result already reached. The result may be precisely the same ..., but no one can be sure of that."
The lesson House teaches is that the courts are generally very cautious about finding that relief would be futile. So long as there is a possibility (even if that is unlikely) of a different outcome, it seems that the courts will not withhold relief from an applicant.