A message from Taoiseach Enda Kenny conveying the Government's alarm over the garda tapes scandal was the "immediate catalyst" for Martin Callinan's shock decision to resign as Garda Commissioner.
The Fennelly Commission has found that Mr Kenny's decision to dispatch the country's most senior justice official to Mr Callinan's Dublin home gave the clear impression to the garda chief that he had lost the support of Cabinet.
The report by Mr Justice Nial Fennelly paints a Government in complete chaos in relation to the handling of revelations that phone calls in and out of garda stations had been recorded for decades.
The commission found that the then Justice Minister, Alan Shatter, was not made aware of the developing events around the recordings, and that personal papers belonging to Mr Callinan were put in black refuse sacks and shredded.
But the most extraordinary and potentially damning findings of the Fennelly Commission relate to the evening of March 24.
A four-hour long meeting at Government buildings - during which the decision was taken to dispatch to Mr Purcell to Mr Callinan's home - was held without any notes being taken.
Later, a "shocked" Mr Purcell travelled to Mr Callinan's Glasnevin home at around 11pm to convey the Taoiseach's message of deep concern.
Although accepting the Taoiseach was not trying to pressurise Mr Callinan, the commission stated: "Mr Purcell's mission was likely to be interpreted as doing just that."
The report adds that "the immediate catalyst for his decision to retire was the visit of the secretary general…and the message that was conveyed to him from the Taoiseach during that visit".
The release of the Fennelly Commission immediately prompted calls for Mr Kenny to consider his position.
In his 300-page report, Mr Justice Fennelly also raises serious questions over some of the decisions taken by Attorney General Máire Whelan, who brought the garda tapes revelations to the Taoiseach's attention.
The commission found that Ms Whelan, a Labour Party nominated AG, did not contact Mr Shatter about the tapes controversy partly because of public remarks he had made about garda whistleblowers, as well as apparent "tensions" between him and Leo Varadkar.
Personal papers belonging to the former commissioner were put into a number of black refuse sacks and subsequently shredded. The findings also state the SIM card in the Garda chief's phone was removed and never recovered.
The report says it has been striking how little documentary evidence is available.
In another extraordinary finding, Mr Justice Fennelly said no notes were available from the meeting in which Mr Kenny decided to dispatch Mr Purcell to Mr Callinan's home.
"No note or record, of any kind, was made of what Mr Purcell was asked to say to the commissioner," it found.
And it is the decision to send Mr Purcell to Mr Callinan's home that has put Mr Kenny under the most pressure.
Importantly for the Taoiseach, the report found he did not sack or remove the commissioner because a Government can only do so by invoking legislation.
In fact, the commission does conclude Mr Callinan made his own decision to step down.
Mr Kenny seized on this finding, insisting he had been effectively exonerated because the commission found no evidence he sacked Mr Callinan.
The former garda chief told the commission he felt he had no option but to step down, as he was left with the impression he did not have the Government's support.
"I want to be very clear, there was absolutely no options put on the table to me," Mr Callinan told the commission.
The following morning, Mr Kenny became aware of Mr Callinan's desire to serve out an additional three months in the post before his retirement.
When this was communicated to Mr Kenny by his chief civil servant Martin Fraser, Mr Kenny replied that the retirement should take place "with immediate effect".