For a while there last week, we were back in the winter of 2007. On Thursday, before the resignation of Willie O'Dea, Brian Cowen was affirming that he fully believed his colleague's version of an unlikely story. After the resignation, Micheál Martin asserted that he, too, was a believer. On the sidelines, Dermot Ahern was putting the boot into the "despicable" behaviour and "guttersnipe politics" of anybody who had the temerity to ask awkward questions about a cabinet member.

All three of these so-called heavyweights were making the same noises when Bertie Ahern was giving evidence before the Mahon tribunal. As Bertie regaled the tribunal with tales of whiprounds and dig-outs and money falling into his lap, his ministers nodded sagely.

In March 2008, just before Bertie bowed to the inevitable, Martin was asked four times whether he believed his taoiseach. "I do believe what the taoiseach is saying," he said.

Dermot Ahern was asked for his opinion of the tales of money madness the same week. "I fully support the taoiseach. I support him in his evidence. I believe him," Ahern said.

Last week, it was déjà vu all over again. Cowen was asked whether he believed Willie O'Dea could have forgotten alleging that a rival was involved with a brothel. "I do believe him," Cowen said. On Thursday's Prime Time, Martin also declared his faith in the gospel according to Willie.

On Friday, Ahern professed his faith once more for O'Dea's story: "He did not deliberately do this. It was a complete mistake on his behalf. Any reasonable person would accept that that is the case." Ahern quite obviously hadn't looked too closely at the circumstances surrounding the affair.

The reaction to the questioning of O'Dea's behaviour says a lot about the approach to ethics and standards in Fianna Fáil. Standards are about getting caught. Unless you are banged to rights, there is wiggle room to break free from any transgression. As long as you can walk out with a straight face and issue some explanation that can't be disproved beyond reasonable doubt, carry on. Loyalty, for constitutional office-holders, is primarily to party colleagues rather than to the state.

When Bertie Ahern resigned, some saw it as the end of an era in which low standards were tolerated by the holders of high office. Ahern's mentor, Charlie Haughey, was primarily responsible for ushering in that era. There was some speculation that, with the passing of the baton to Cowen, proper standards might once again prevail.

The efforts to hold onto O'Dea, to bounce the Greens into a quick confidence motion, to attack the opposition for raising the matter, all point to the conclusion that nothing has changed.

Instead of offering fidelity to the constitution, Cowen and his ministers rallied to Willie's cause. Standing by your own was more important than doing the state the service it deserves.

The notion that O'Dea was a victim of political bloodsport is nothing short of ludicrous. O'Dea has long played fast and loose with both the law and people's reputations in pursuit of political advantage. The difference this time was that he was found out.

In November 1998, Bertie Ahern was peeved at the storm being kicked up by publication of a biography which raked over his personal life. Ahern himself had sanctioned and signed off on the content, but his acolytes were not initially aware of that.

O'Dea rushed to his leader's cause. He penned an article for the Sunday Independent that assailed the character of the two authors, Ken Whelan and Eugene Masterson. In time, the newspaper settled a legal action with the authors, paying out over €50,000. No skin off O'Dea's nose. He was indemnified and lived to defame another day.

O'Dea had an equally cavalier attitude to his position as a government minister when Bertie Ahern was before the Mahon tribunal. In September 2007, Ahern was under serious pressure at the inquiry. O'Dea was quoted in a front-page story in the Sunday Independent on 16 September declaring that the inquiry was acting improperly.

"O'Dea accuses tribunal of acting outside its remit in public trawl of taoiseach's finances", read the headline.

O'Dea, in his capacity as barrister and law lecturer, was offering his considered opinion on the inquiry. It was a serious charge that could be interpreted as questioning the capacity of the three judges to act with impartiality. If O'Dea believed what he said, he was obliged to bring his concerns to cabinet and to the floor of the Dáil. The tribunal derived its power from the Oireachtas. If it was acting outside the law, parliament was obliged to rein it in or disband it.

Far from doing that, Willie buttoned his lip. He refused to comment further on his allegation. He had thrown it out for public consumption, but he knew if he elaborated he might be getting into choppy waters. He ignored his constitutional duty for the sake of blackening the tribunal in the public square.

This time, he got caught. Maurice Quinlivan, the Sinn Féin candidate in last June's local elections, hit a nerve with a standard political attack on O'Dea. Quinlivan released a statement condemning the employment by O'Dea of six public servants in his Limerick office. Willie hit back with all the venom he could muster.

"There was a house owned by him that was rented out and they found two ladies of the night operating in there in the last couple of weeks," he told Limerick Chronicle reporter Mike Dwane.

It was an outrageous slur, even by the standards of mud-slinging that apply in the heat of electoral battle.

When Quinlivan sued, O'Dea's first shot was to shift blame. In legal correspondence with the newspaper on 27 March, he suggested that it was the reporter who brought up the subject of the brothel. Luckily for Dwane, he had a tape of the interview.

O'Dea signed an affidavit on which his memory of blackening Quinlivan failed him. Crucially, he didn't bother to check with the reporter what exactly he had said. If he had checked, or remembered his comments, and admitted them in the affidavit, serious trouble would have beckoned. He would have been subject to an injunction and liable for prosecution under the 1923 Electoral Act, which includes a provision that could have banned him from holding public office for seven years.

Ruling on the injunction application in April, Judge John Cooke refused it because of O'Dea "categorically and emphatically" denied he had made the offending statement.

So it was fortunate at that stage that his memory failed him. Brian Cowen, Micheál Martin and Dermot Ahern all accept that O'Dea's memory conveniently malfunctioned.

He might well have expected the problem to disappear after the election. But Quinlivan persisted, and eventually the reporter's tape surfaced to reveal the damning comments.

All was not yet lost. O'Dea agreed a settlement. At this remove we must assume that it was a coincidence that the two-minute settlement hearing took place on 21 December, the last day of the law term, when the world has its mind on other things. We must assume that it was a coincidence that the judge who was asked to rubberstamp the settlement was John McMenamin, rather than John Cooke, who had ruled on the injunction back in April.

If Cooke had presided over the settlement, he might have had something to say about the false affidavit that had formed the central plank of his ruling in April. It is against this background that the spurious claim that "the courts had dealt with the matter" was made by O'Dea's apologists last week.

He might still have skipped free. A public act of contrition – even through his newspaper column – might have seen off further inquiry, but he decided to tough it out.

Fine Gael senator Eugene Regan attempted to raise the matter in the Seanad on 4 February. He was shouted down. A newspaper column referred to it on 7 February. The following Thursday, Regan tried again to bring it up in the chamber. O'Dea's response was key to his ultimate downfall.

He dispatched a solicitor's letter to the newspaper, demanding damages and an apology. He used his own newspaper column to attack Regan personally over an incident involving the senator's brother.

Having kicked into life the sleeping dogs of media and opposition, Willie continued to bluster and rail against dark forces trying to do him down. He correctly guessed that Cowen and his cabinet would stand square behind him rather than pursuing standards befitting high office. It was all down to whether or not the bedraggled Greens could be cajoled or conned into coming on board.

It nearly worked. Nothing but the tweeting Dan Boyle stood between Willie and the latest mess in which his big mouth had landed him.

And so it was that O'Dea became the first government minister to be tweeted out of office. He has paid a high price, but he need only address a mirror to identify who is to blame.