Her quick toilet stop became a terrifying half-hour ordeal in which she believed she would die.
Moore, who appeared in the Dunedin District Court yesterday, bundled her into the toilet and grabbed her around the throat to stifle her screams.
The victim stopped resisting and began speaking to Moore "in an effort to humanise herself with him, as she believed he would kill her when he had finished with her'', police said.
He told her it was the first time he had ever raped someone.
And he did it repeatedly.
"It involved a variety of violent sexual acts, it extended over a considerable period of time and it's had a profound impact on this woman,'' Judge Michael Crosbie said.
"The effects on her are as profound as any I've ever read ... You preyed on her with devastating consequences.''
In a statement, read by Detective Dave Checketts, the victim said she had previously been a cheerful and optimistic person but was now cautious and would not go anywhere alone.
When she was initially examined by a doctor, they found she needed an IUD implanted to quash the risk of pregnancy.
It resulted in two failed attempts in Queenstown before a trip to Dunedin and two further agonising procedures while "the fear was fresh in my memory''.
"It is a pain I have never felt before,'' the victim said.
Because her mother was unwell at the time, the court heard, she did not want to trouble the family with her own suffering.
The woman died never knowing her daughter's torment.
"[I had] no chance to cry in her arms. This yin and yang are separated,'' the victim said.
After Moore had finished with the woman in the toilets, he told her to wait until he had driven off before leaving, so she could not record his registration plate.
She complied but when police trawled through CCTV footage of vehicles passing nearby the scene they soon identified the defendant.
Initially, he told them the sex had been consensual but later pleaded guilty to a charge of rape.
"This, for you as a person, is a massive fall from grace,'' the judge said.
A psychological report on Moore revealed he had suffered significant trauma in his childhood and unravelled the stresses in his marriage.
"None of that excuses what you did,'' Judge Crosbie said.
Defence counsel John Westgate said Moore fully accepted the devastating effect his crime had on the victim, and his life too had been decimated.
"His marriage is over, relationship with his kids is over, his professional life is over and he's going to jail for a very long time,'' he said.
Moore was sentenced to six and a-half years' imprisonment.
