A former archbishop has settled his action against RTÉ and, significantly, no damages have been paid by the broadcaster. The case taken by Richard Burke over Mission to Prey will go down as a minor postscript to what was, more generally, a major embarrassment of a programme.

The edition of Prime Time Investigates in which RTÉ libelled Fr Kevin Reynolds was broadcast four years ago, on a Monday in May 2011 when the national news agenda was dominated by a much happier showpiece event for RTÉ – the visit of President Barack Obama and Michelle Obama to Ireland.

Long after the glow of Obamamania faded, Mission to Prey continues to be cited as an obvious example of RTÉ failings, sometimes by politicians who have quite separate axes to grind against the broadcaster.

The Fr Reynolds libel (in which RTÉ falsely alleged he had raped a young woman in Kenya and fathered her child) was an especially bad error because it opened up the broadcaster to the criticism of religious commentators who repeatedly claim RTÉ is inherently biased against the Catholic Church and its beliefs on a variety of issues.

Then there were the official sanctions. The Broadcasting Authority of Ireland (BAI) found that by broadcasting so flawed a programme, RTÉ had “seriously breached” the Broadcasting Act 2009 and fined it €200,000.

A BAI-commissioned report written by Anna Carragher, a former controller of BBC Northern Ireland, did not hold back, finding that journalistic standards "fell short" and concluding that the production team responsible had descended into "groupthink".

By the time Carragher’s report was published, that group of journalists was already no more, its members having either departed RTÉ before the scandal broke, resigned or retired in its aftermath or been redeployed elsewhere in the organisation.

Six months before the BAI published its findings, RTÉ director general Noel Curran had gone on the Six-One news bulletin to announce a review of RTÉ's editorial processes and confirm the suspension of Prime Time Investigates, the flagship series he had launched in 2003.

A full restructuring of RTÉ Television's current affairs department followed, while in 2012, the controller of the BBC News Channel, Kevin Bakhurst, was brought into RTÉ as managing director of news and current affairs.

Bakhurst now doubles as RTÉ's deputy director general and is frequently called upon to explain at forums, such as Oireachtas communications committee meetings and journalism conferences, that lessons have been learned since 2011 – a year also marred by the notoriously erroneous use of a tweet during the Frontline presidential debate.

The public flak has also come from dismayed internal sources. Last February, senior news presenter Bryan Dobson used his inaugural lecture as adjunct professor of public service broadcasting at the University of Limerick to say the appetite for edgy, ground-breaking journalism had led RTÉ to "devour good editorial practice" when it screened Mission to Prey.

Meanwhile, in her 2014 book Inside RTÉ – A Memoir, former RTÉ producer Betty Purcell interpreted the dawn of a more tabloid culture within the station's news and current affairs department around the time of Mission to Prey as a response to improved ratings at TV3.

This was subtly damning. RTÉ should, of course, be able to cope with competition from the likes of a Vincent Browne discussion show without self-destructing. On the other hand, though, investigative journalism is, by definition, a high-stakes activity. Mistakes will be made no matter how many precautionary measures are in place. The wider problem is that RTÉ is one of the few media organisations that can afford to commit to investigative journalism.

The risk, as it sees it, is that it might not always be in a financial position to do so.