Máiría Cahill has said the Future of the Media Commission has questions to answer, following the resignation of Alan Rusbridger from it.
The Guardian's former editor-in-chief announced he was stepping down on Sunday.
In a statement, he said: "The unanimous support of my commission colleagues was very important to me.
"The commission is considering critical issues for Ireland and I don't want my involvement to be a distraction from its work".
Last week, Ms Cahill accused Mr Rusbridger of 'failing spectacularly' in his responsibilities while he was editor of veteran columnist Roy Greenslade.
Mr Greenslade recently revealed he supported the IRA's 'political ambitions', although said he began to 'doubt its bombing tactics' over the years.
He also confirmed he wrote columns for Sinn Féin newspaper An Phoblacht under the pseudonym George King.
The Guardian has apologised to Ms Cahill over an article Mr Greenslade wrote in 2014, while Mr Rusbridger has also apologised for the column's publication.
On Monday, Ms Cahill told Pat Kenny: "I don't think anybody really comes out the winner in this at all.
"I think it's been a very difficult fortnight - I accept now that Alan Rusbridger has resigned, I think he should have done it last week.
"However he's done it now."
She said while she is not sure what her feelings are on the subject, "I think it was the right thing to do, and ultimately he did the right thing in the end."
Ms Cahill said she received an e-mail from Mr Rusbridger two weeks ago but had not replied.
"I hadn't replied to it at that point, I wanted to take time to do so - and I also, as you can appreciate, wanted to take advice.
"But I hadn't heard anything since then - but I can appreciate for Alan Rusbridger it's probably been a very difficult time too.
"He has apoligised personally to me - he actually also went a bit further and said had he known about Roy Greenslade's IRA sympathies at the time, he wouldn't have published the blog in the first place".
'Potential conflict of interest'
Ms Cahill also said The Guardian has removed three of Mr Greenslade's articles.
But she said Mr Rusbridger - and the commission itself - still have questions to answer.
"It wasn't just about Roy Greenslade and his IRA sympathies, it was about any potential conflict of interest that may have been in the public domain that Alan Rusbridger may have known about.
"I think he could have been a bit more transparent around that and answered those questions.
"But I also think that the Commission for the Future of Media have questions to answer as well.
"They unanimously declared support in a move which I found out on Twitter, which upset me greatly last week.
"And I would have appreciated had any of them there - and maybe this is the wrong way to look at it - but I think that women in particular are more empathetic.
"There's six women serving in that commission - anyone of them could have lifted the phone to me to check facts or accuracies in which I was saying against what Alan Rusbridger was saying.
"They didn't do that, and I think that is deeply regrettable".