NZR has issued them a formal warning which will sit as a "black mark" on their record.
Its internal investigation found that while the performance was legal and consensual, it was wholly inappropriate for professional rugby teams to engage in events of this nature and players should take collective responsibility.
The letter, which has been signed by many high-profile New Zealand women, said the investigation "has highlighted to all New Zealanders that NZ Rugby's judiciary process is not appropriate for dealing with issues of integrity, mana, respect and basic personal rights".
Blue said it was time for NZR to address its "internal culture issues".
"The internal investigation into the incident involving Scarlette and members of the Chiefs rugby team has highlighted to all New Zealanders that NZ Rugby's judiciary process is not appropriate for dealing with issues of integrity, mana, respect and basic personal rights.
"NZ Rugby has previously refused to take up offers of support and expertise from external parties with these sorts of investigations. Until they do, these investigations will continue to produce the exact same results.
"The open letter is about letting NZ Rugby know that enough is enough and we want them to take us up on our offer to support them through this process.
"As much as New Zealanders love rugby - we need New Zealanders to respect women."
Other prominent signatories included Sexual Violence Survivors advocate Louise Nicholas, MPs Jan Logie, Ruth Dyson and Tracey Martin, social justice advocate Catriona McClennan and Barbara Williams of the National Council of Women.
Tew said NZR would speak with Blue "as a priority on what more we could do".
"By way of context, in recent years, New Zealand Rugby has ramped up programmes that provide education for players as they enter our environment," Tew said.
"These include our induction programmes for professional players which deliver modules relating to risk awareness and their heightened responsibility as public figures, social media, healthy relationships and mental well-being."
NZR was expanding the work, developing a "respect and responsibility education programme" focused further on healthy relationships and consent issues.
It has also begun advertising for a "respect and responsibility manager" to lead it, and is working with six other codes.
The letter followed earlier rebukes by Prime Minister John Key and All Blacks coach Steve Hansen today, both saying that lessons had to be learned from it.
"We are brought up in New Zealand to have respect for women," Key said.
And what looks to be the case in this particular instance is that wasn't on display.
"So I would hope the Chiefs would quietly just step back and learn from that.
Asked about the report, Key said he had not read it fully but doubted NZR would have tried to sweep it under the carpet.
"I think they would see the severity of the situation."
He said he agreed with Hansen there was no place in the sport for such events.
"I concur with that view. So whatever the outcome of the actual report there will be quite a few lessons I think that will be absorbed by management, both of the Chiefs and others."
At a press conference yesterday, Tew said the organisation did not have grounds to pursue misconduct against individual players.
Tew said witness accounts and the investigation led NZR to conclude action could not be taken against any individual player.
He confirmed NZR wouldn't ban Mad Monday events, but would try to influence them to be more family-orientated.
The letter reads:
Right now, thousands of New Zealanders are questioning the culture of our country's favourite sport and those in charge to do better.
We are writing to you publicly in the hope that you will listen to our calls for you to act with courage.
The internal investigation into an incident involving a woman called Scarlette and members of the Chiefs rugby team has highlighted to all New Zealanders that NZ Rugby's judiciary process is not appropriate for dealing with issues of integrity, mana, respect and basic personal rights.
We are offering our expertise, experience and support. Louise Nicholas has been working alongside NZ Police to successfully enhance their internal culture for some time now. We encourage you to do the same. Dr Jackie Blue offered to assist a month ago and this offer still stands.
Rugby is like a religion in New Zealand, with players worshipped by young kiwis throughout the country. NZ Rugby could not operate without thousands of women volunteers and players in clubs and towns across the country: we must address the culture that exists from the top down and set the right example, particularly for our young New Zealanders.
Now is the time for you and those involved in the incident with Scarlette to be courageous and to take personal leadership on an issue that we can all work on addressing together.
As much as New Zealanders love rugby - we need New Zealanders to respect women.
We look forward to hearing from you.
#LoveRugbyRespectWomen
Signed,
• Dr Jackie Blue, EEO Commissioner
• Louise Nicholas, Sexual Violence Survivors Advocate
• Prue Kapua, National President, Maori Women's Welfare League
• Barbara Williams, National Council of Women
• Caren Rangi, National President, P.A.C.I.F.I.C.A (Pacifica Allied (Women's) Council Inspires Faith in Ideals Concerning All) Inc
• Dame Susan Devoy, Race Relations Commissioner
• Nive Sharat Chandran, Co President YWCA of Aotearoa New Zealand
• Sina Wendt-Moore, Co President, YWCA of Aotearoa New Zealand
• Monica Briggs, CEO, YWCA
• Karen Johansen, Indigenous Rights Commissioner
• Jan Logie, Member of Parliament
• Ruth Dyson, Member of Parliament
• Tracey Martin, Member of Parliament
• Catriona McClennan, Barrister and Social Justice Advocate
• Leonie Morris, Auckland Women's Centre
• Eileen Brown, Council of Trade Unions
• Sue Kedgley, UN Women
• Dr Kim McGregor QSO , Director of Tiaki Consultants.
• Vicky Mee, Business and Professional Women
• Jane Drumm, Shine
• Erin Polaczuk, PSA
• Deborah McKenzie, Inner City Women
• Christine King, President, Pacific Women
• Denise Ritchie, Stop Demand
• Dr Janette Irvine
