The National Standards Committee appealed against the penalty decision, arguing he should have been struck off or suspended for three years.
Gardener-Hopkins meanwhile cross-appealed, arguing for a shorter period of suspension.
In a decision released today, the High Court declined the cross-appeal, and extended the time of suspension to three years, along with censure and costs.
"Mr Gardner-Hopkins' conduct was serious, exploitative, sexual misconduct," the court held.
"It was not the conduct of a fit and proper person."
The decision noted Gardner-Hopkins had taken steps in the six years since the incidents to address the "underlying issues", and the risk of any repeat of such behaviour was "substantially diminished".
The court found suspension rather than striking him off - preventing him from practising as a lawyer - was appropriate.
However, the court accepted the Tribunal was wrong in accepting financial and professional consequences to Gardener-Hopkins, and considering the case was less serious than others.
"For that reason and to maintain public confidence in the profession and the standards it held practitioners to, it was necessary to impose the maximum period of suspension," the court held.
During the tribunal's liability hearing, former summer clerks said Gardner-Hopkins touched them inappropriately, with one woman describing that she felt like a "piece of meat".
Human resources and the firm's board were made aware of the allegations against the then leader of its environmental planning and natural resources team.
In January 2016 an incident with one of the victims was revisited with Gardner-Hopkins by the firm's chief executive and board members after another incident with the young woman and another lawyer in the firm.
Following meetings in early February 2016, where Gardner-Hopkins apologised and admitted he had misled the chief executive and the senior partner, he was told his position was no longer tenable.
It was agreed he would resign and quickly leave the firm. However, Gardner-Hopkins' departure was announced to the rest of the firm — with advance notice having been given to the summer clerks — in "glowing terms".
He was also still at the firm from time to time.
"The summer clerks described how difficult his presence at the firm was for them. They perceived that Mr Gardner-Hopkins' departure was announced in an artificially positive way," the liability decision read.
Some of the victims have left the profession, while others changed to different areas of law.
"As one of them explained during the liability hearing, the fact that they were not safe from a partner, led to a feeling that they could not be safe anywhere in the workplace," the tribunal's decision read.
The case began after the victims obtained legal advice and made a complaint to the NZLS in 2018. When the allegations emerged into the public arena it led to an outpouring of media coverage and social commentary in the midst of the MeToo movement.
"It is probably fair to say that these events, and the outcomes which followed the two reports of the inquiries, called out unacceptable behaviours and have led to significant changes in many workplaces in the legal profession," the tribunal noted.
Dame Margaret Bazley led an external review into Russell McVeagh and the allegations from the summer of 2015/16.
She interviewed 250 people and in her 89-page report found junior lawyers and staff were encouraged to "drink to excess".
Bazley also found a culture with instances of crude, drunken and sexually inappropriate behaviour. She noted failings in the firm's governance and policies, including no code of conduct, which she said contributed to poor incident management.
Six pages of recommendations advocated for sweeping changes to address bullying, the sexual harassment allegations and company policies.
Russell McVeagh accepted all of the findings and said it would implement all the recommendations.
As a series of scandals rocked some of the country's top law firms, a 2018 Law Society survey of more than 3500 people found about one in three female lawyers has been sexually harassed at some time during their career.
A regulatory working group established by the Law Society and chaired by Dame Silvia Cartwright further examined issues in the legal profession.
It found female lawyers have been subjected to "sexual objectification" for decades and made several recommendations, including new rules for lawyers which specifically require high personal and professional standards for sexual harassment, bullying and discrimination.
