"We know that this stuff is happening in New Zealand all the time at a level which is just embarrassing."
He said domestic violence usually hid in silence.
A key difference with Millane's case was the fact she started out as a missing person, then the public slowly began to learn more about her and her travels around the world.
"But in this case this is quite different. We had a missing person, the photos were put out there, people started to learn more about the young woman and then when the tragic news occurs there's an emotional connection."
He said he now hoped something good could come out of the tragedy as it basked in shame under the world's glare.
"For New Zealand perhaps it's a wake-up call that we have these terrible levels of violence towards women."
A key way to improve would be changing the attitudes of a lot of men who looked at women as "chattels" or sexual objects rather than human beings, he said.
Kiwi men needed to learn about "respectful relationships" which included treating their partners as equals, ditching gender roles in the home, listening to them and "enthusiastic consent" in regards to sexual activity.
Jane Drumm, general manager of anti-domestic violence specialist organisation Shine, said the first thing people needed to understand about the case was that Millane "did nothing wrong".
"It's really important not to blame the person who ended up being hurt or killed because there's a whole lot of things that people could leap to or assume that this young woman or other women should have done or thought to have not put themselves in a position where they ended up being hurt.
"It is an absolute right for anyone to go about their business, to meet up with people, to be able to have the freedom to do normal things without having to fear for their safety or their lives. That should just be a normal human right."
She said most people were nice and respectful, but there would always be the odd person who wasn't.
"So be cautious. Take your time to get to know somebody."
She said online dating, including use apps like Tinder, may be how people met each other in 2018, but it didn't mean it was a safe option.
"[Online dating] encourage people to jump into things where they don't have any particular social context for meeting somebody.
"It is life but it's dangerous."
While it was now a new reality, she urged people to be careful and always meet in public places.