The Broadcasting Authority of Ireland, which oversees impartiality in broadcasting, said RTE played down "significant" errors in the making of the programme which scuppered the chances of Sean Gallagher becoming president.
In an embarrassing move, the BAI has demanded RTE now release every detail of a probe into the programme.
Earlier this week RTE managing editor of current affairs David Nally admitted the programme ended the chances of then presidential front runner Mr Gallagher. An internal RTE report leaked at the weekend found no evidence of "bias" but raised concerns about how questions for the candidates were drafted and how the audience members were selected.
But the BAI yesterday said the "editorial failings of the programme were more significant" than the report RTE released.
Today, Rob Morrison, an external author of the probe report, "absolutely refuted" the claims of the Broadcasting Authority.
Mr Morrison, head of television news and current affairs at UTV, said all information relating to the RTE investigation into the programme, which he co-authored, had been handed over to the Broadcasting Authority of Ireland.
The report he produced was an "absolute reflection" of all the information gleaned during the compiling of the report, he said.
And RTE chiefs stated they were "fully satisfied" the report was an "accurate" representation of the editorial failings.
The show's presenter Pat Kenny challenged the broadcasting authority to point out exactly where the station was "less than honest".
Mr Kenny said: "It would be helpful if the compliance committee could point to the short and the long document and indicate where they thought RTE was being less than honest. That would be helpful."