Taoiseach Leo Varadkar says ex-Rehab chief executive, Angela Kerins, was "treated very badly" by the previous Dáil public accounts committee during its pursuit of serious financial issues at the organisation.
Mr Varadkar rowed into the case, saying politicians must not be "driven by news cycles" after the Supreme Court on Wednesday ruled the previous PAC acted unlawfully during meetings with her in 2014.
Speaking at a rare meeting of the Oireachtas working group of committee chairmen - which was not attended by the group's own chairwoman, TD Maria Bailey amid ongoing controversy over her dropped legal case - Mr Varadkar was asked for his views on the supreme court ruling.
The case was raised as the verdict has potentially significant implications for the ability of Oireachtas committees to question witnesses on public interest matters.
Mr Varadkar initially said he was reluctant to answer the question as he has not read the ruling in depth. However, he then continued that in his view Ms Kerins was "treated badly" by the previous PAC.
"The FAI meetings [with the sports committee this year] showed the power of Oireachtas committees and that you can actually hold people to account. At the same time I have to confess that I do believe that the previous PAC did treat some witnesses very badly a few years ago.
"If you are going to act in a judicial way and make judgments on individuals, well then you have to do it in a fair way. You have to listen to all the evidence.
"You have to not comment on it until you have heard all the evidence and then come to your conclusions in a judicious way that should not in any way affect how the public see you," he said.
During the same meeting - which is organised to allow Oireachtas committee chairs to question the sitting Taoiseach on specific areas - Mr Varadkar warned Britain that the EU "cannot continue to have a rolling extension" of Brexit deadlines.
Since outgoing British prime minister Theresa May announced she is stepping down, a number of potential successors have insisted they will be able to delay Brexit and strike a new exit deal.
However, while Labour leader Jeremy Corbyn has also said this is possible and met Mr Varadkar in Dublin today, the Taoiseach said the latest October deadline will not be pushed out further: "There is a hardening view across the EU that we cannot continue to have a rolling extension of deadlines.
Mr Varadkar also said the State may need to introduce "electronic counting" of votes in light of the marathon Ireland South European elections stand-off but ruled out the separate "electronic voting" system.
The Taoiseach also said exit polls may need to be reviewed in light of the incorrect initial predictions, and repeated his view that construction firms with poor records should not be allowed to receive new Government contracts.