Unwavering duo stick by their stories
There are a number of key differences between the version of events being offered by Gerry Adams and Austin Stack but the origins of the names sent to the Garda Commissioner is the biggest.
Mr Adams has maintained he was supplied four names by the murdered prison officer's son but this is hugely contested by the Stack family.
The Sinn Féin boss says that at a meeting in 2013 he received two names and that he was subsequently supplied with two others. It was February of this year by the time he decided to email this information to the Garda Commissioner.
Mr Stack said yesterday: "I didn't give any names to Gerry Adams of individuals who I thought had any hand, act or part to play in this investigation.
"There were four people in the room that night. Nobody took notes."
He speculated that a recording may have been taken on a mobile phone.
However, in his Dáil speech on Wednesday Mr Adams said he received the names from Mr Stack.
"Austin denies giving me names. Why on earth would I say that I received the names from him if I did not?
"In February of this year, Austin Stack also claimed that he gave the names to the Fianna Fáil leader, Micheál Martin.
"If Austin Stack was prepared to give names to Mr Martin, why would he not have given them to me? I was, after all, the person he was asking to arrange a meeting," Mr Adams said.
"At Austin's request, I contacted those I could among the names he gave me. They denied having any information about the killing of Brian Stack. I told Austin Stack this."
During his speech, Mr Adams suggested IRA figures were protected by the peace process, pointing to the operation of the Independent Commission for the Location of Victims' Remains.
"The commission also meets former IRA people. Should they be named?" he asked.
"All of this progress was only possible on the basis of confidentially and trust. That is why no IRA people were named during any of these initiatives and why they should not be named today."
However, Mr Stack said: "There is no amnesty in place. Everybody who has committed a crime has to be brought before the courts. Gerry Adams trying to wrap the peace process around this is not valid."