Seán Gallagher said he was met with hostility and arrogance from RTÉ when he initially complained about the broadcast of a tweet on the Frontline debate.
The Broadcasting Authority of Ireland later upheld a complaint made by the former presidential candidate about the tweet which was incorrectly attributed to the official ‘Martin McGuinness For President’ twitter account.
Speaking at a media conference in Dublin, Mr Gallagher said RTÉ still has questions to answer about the issue.
Mr Gallagher said that he felt a sense of injustice about the tweet.
He told the conference that he first raised the matter with RTÉ and was gobsmacked by their arrogance and "the almost hostility" of the response, saying there was no sense of contriteness or apology.
He also said he applied for information about the tweet under the Freedom of Information Act and that this was refused and a request to meet with RTÉ’s Director General was declined.
He said it was at this stage he decided to take the matter to the BAI. He said the BAI came under pressure not to support his claim but they showed great honesty in dealing with it.
Mr Gallagher said there were similarities between how the broadcaster dealt with his case and with the Fr Reynolds case, and RTÉ's reaction was like how the Catholic Church reacted to claims of abuse - it went into defence mode and compounded the original injustice.
In a statement, RTÉ said it had accepted the BAI decision in March and that both the broadcaster's Director General and the Board had apologised to Mr Gallagher.
An editorial review was instigated and an editorial standards board was set up to monitor content.
This board will also play a role, the broadcaster said, in a restructured complaints process.
The future of the media is the focus of the conference, which is taking place in Dún Laoghaire.
‘’Media Future’’ is looking at the transformation of the media, key trends and technologies.
The Huffington Post Media Group, The Wall Street Journal, Al Jazeera English and Wired.co.uk were some of the major media organisations represented at the conference this morning.
