A district court judge has upheld an appeal by Dr Powell, a member of ACC lobby group Acclaim Otago, against being required to sign the ACC form, called ACC 167.
Two just-released decisions from the district court say ACC acted unlawfully when it told two clients they must sign a consent form gathering private information or face having their claims cut off.
One case involved Dr Powell, and the other a client with a traumatic brain injury.
Judge Grant Powell heard both cases, upheld both appeals and awarded costs against ACC.
Dr Powell said she and other claimants had unsuccessfully tried to raise concerns with ACC about the excessively broad consent form since 2009, including through two official ACC liaison bodies, of which she has been a member.
After a major privacy breach by ACC the previous year, an independent review team commissioned by the Privacy Commissioner took issue with the form in 2012, and ''strongly'' encouraged ACC to consider ''detailed consultation'' with people affected by any review.
Dr Powell said ombudsmen had already been appointed in several other areas, including banking, and having a fully independent ACC ombudsman would help deal with issues such as the consent form.
An ombudsman would not be an alternative complaints service, but would allow areas of genuine concern to be dealt with effectively.
ACC had been implementing a series of recommendations arising from the privacy review report.
But the privacy of injured ACC claimants involved their personal ''integrity'' and morale and many claimants believed this issue should have been given a higher priority, she said.
Another ACC claimant, whose name was suppressed by the court, and whose consent form-related appeal was also upheld by the court this week, said the outcome meant ''a huge step forward for all New Zealanders and not just for accident victims'', by raising awareness of wider privacy issues.
ACC senior media adviser Glenn Donovan said that after the recent court decision, which differed from previous court decisions, changing the consent form was now an ''urgent priority'' and ACC was working to make changes as soon as possible.
ACC had already actioned 37 of the 44 core recommendations of the independent privacy review.
