Then she said: "I don't want to continue this conversation," and hung up. She has remained incommunicado ever since. This led quickly to three realisations. First, I was countenancing the near certainty that in the areas of her story where I had given her the benefit of the doubt, I had been wrong to do so. Second, I had not considered the possibility that her story had been carefully constructed on a foundation of embellishments, false memories and fabrications. Third, I owed an apology to the NSW Police because the column had created the clear impression of police indifference towards this alleged crime. The Police Commissioner had responded promptly to the allegation contained the column, and the woman had declined to assist the police.

Nobody but her knows what happened, and although I was given a considerable number of details about her experiences that were credible, I acknowledge that there was not enough definite information to justify writing the story. Prior to writing the column I had Googled her name, and checked our files, and found no red flags. Now all I could see were flashing red lights, barriers and sirens. During four hours of interviews conducted over four conversations, when I pressed her about why there was no complaint in the system, an obvious red flag, she had claimed she had gone to report the crime six months after the alleged event, but been told by a police officer that she had waited too long, had no evidence and there was no credible claim to make. I failed to test that claim adequately. The default position in listening to claims of sexual assault is empathy, but for journalists empathy has to be accompanied by an interrogatory quest for detail, consistency and conviction.

She did provide detail, consistency and conviction. She did speak with an authentic voice about the milieu of homelessness, drug addiction and prostitution in and around Kings Cross and Darlinghurst. She did address the fact that she had psychological problems. She told stories about her own volatility and erratic behaviour, which, ironically, aided her credibility. I had no doubt that she believed the root cause of her problems was sexual assault. It was also unremarkable to hear a complaint of police inertia in response to a belated and uncorroborated claim of sexual assault. In 2006, the NSW Domestic Violence Coalition and Redfern Legal Centre sent a submission to the NSW Ombudsman trenchantly criticising the way police were responding to assaults on women. The Ombudsman published a report in 2006, 'Domestic Violence: improving police practice', recommending changes to the way police respond to assaults against women. Another context for my thinking was that Sydney experienced an epidemic of rapes and sexual assaults between 2000 and 2002, and the majority were unreported to police. On July 29, 2001, The Sun-Herald published a front-page story which began: "Police examining more than 20 brutal attacks on teenaged girls in just 10 months ... hospital records and police data show that at least another 50 similar incidents have been reported in the Bankstown area of south-west Sydney over the past two years."

This estimate is consistent with the underreporting of sexual crimes, with the consensus in criminology that about 80 per cent of such crimes do not enter the criminal justice system. Finally, I had what I thought was an understanding that Louise was seeking justice, and that I would be helping her. These elements were the context – I'm not claiming them as sufficient justification – for my decision that I had sufficient credible detail to proceed to publication, with the obvious caveats that there was no record of this woman's name in the system in regard to the alleged crime, and that these were allegations. After publication I learnt that a woman had made very similar claims of rape during two rallies last year organised by Reclaim Australia, which opposes militant Islam. When I sought to speak to Louise about this she was unresponsive.

In the story recounted to me by Louise, she made insulting references to rapes committed by Middle Eastern men. I had wrongly amplified this insult by including her words in the column. Had I known on Sunday what I knew by Wednesday, the column would not have been written. Hindsight has a ruthless clarity. Twitter: @Paul_Sheehan_ NSW Rape Crisis 1800 424 017