She continued: "We need to establish, in relation to that particular meeting, who was right and who was wrong. Was the Commissioner being fully frank, or was she not?"
That's classic McDonald.
With her back to the wall after facing difficult questions about her latest embarrassment, she resorted to her tried-and-tested method of deflecting attention by pointing to the failings of others while self-righteously posing as a seeker after truth. And this woman is tipped to become Tanaiste or - God help us all - even Taoiseach.
What McDonald had already done in trying to escape political contagion from the disgrace of her erstwhile protege Jonathan Dowdall, found guilty with his father of falsely imprisoning, torturing and terrifying someone he believed intended to swindle him, was by any standards nauseatingly hypocritical.
The facts are straightforward. Dowdall resigned as a Dublin Sinn Fein councillor in 2014 after a few months pleading ill health and McDonald described him as a hard worker who would be missed. The following year he split from the party, alleging he'd been bullied.
At the end of last month, sensational reports from the Special Criminal Court included evidence that a video from January 2016 showed Dowdall telling the victim that he was a "stupid dumb f**k to mess with the head of the IRA" who was a friend of Gerry Adams and McDonald. Sinn Fein tweeted a short press release quoting McDonald expressing her shock, welcoming the conviction and hoping for a sentence that would reflect his victim's "trauma".
"Jonathan Dowdall left Sinn Fein some years ago," she ended. "He subsequently worked with, and supported, a political opponent of Sinn Fein in the Dublin Central constituency."
She then sent a tweet showing Dowdall with Independent councillor Christy Burke, who left Sinn Fein in 2009.
"This terrible story of thuggery carried all day," was the pious message from a woman who defends as justified the IRA's 30 years of murder, torture and all kinds of criminality. "This photo clarifies political allegiances of convicted person."
She attached also a tweet from Burke in September 2015 welcoming Dowdall to his canvassing team.
Burke, who had met Dowdall only once, was understandably livid, and accused McDonald of "stooping to a new low by a public representative in my constituency and I've been a public representative for 30-odd years".
There are apparently at least 30 photos of Dowdall with McDonald, and the internet was soon adorned with fetching photographs, including one which also featured Gerry Adams.
McDonald dodged the media for as long as she could, but last Friday on the radio she demonstrated why she deserves first-class honours in Shinner Shamelessness. Her tweet had not been unfair, she insisted: "Absolutely not. In putting the photograph to the public domain, it is simply to establish the full story of what happened then and I think Christy understands that."
I cannot abide McDonald, not least because there's no excuse for her choosing the path she did at 30. In some ways I find her worse than the awful Adams, who was born into republican royalty and would have disappointed had he not gone into the family trade.
But McDonald had a privileged background. Her parents were Fianna Fail; she had a comfortable Dublin 6 upbringing; went to a fee-paying private school; read English literature at Trinity; European integration at the University of Limerick - and among her jobs had a year teaching in Spain and a spell in the intellectually respectable Institute of European Affairs. She had many choices.
She joined Fianna Fail in 1998 but soon defected to Sinn Fein where Adams became her mentor. She passed without apparent distress a series of loyalty tests that included speaking in 2003 at a rally in honour of Sean Russell - the Nazi collaborator who was chief-of-staff of the IRA when in 1940 he died of a burst ulcer on a U-boat taking him home from explosives training in Nazi Germany.
She has consistently honoured murderers and torturers who did far worse things than Dowdall, albeit in the name of Ireland.
An MEP from 2004, she became a TD in 2009, and soon displayed a natural talent for aggression and contemptuousness. It was the merciless McDonald who made the life of Ceann Comhairle Sean Barrett a misery, and refused to join the rest of the Dail in applauding him when he retired.
It was she who in 2014 named six former politicians - later found to be innocent - as having held illegal offshore Ansbacher accounts. She was unabashed when the Dail oversight Committee on Procedures and Privilege described her conduct as "defamatory" and "an abuse of privilege".
Yet this same woman, refusing to get involved with the Sinn Fein people alleged to have information about the murder of prison officer Brian Stack, said unblushingly: "I think that people have an entitlement to their good name."
McDonald is, of course, notorious for leading the chorus of "I believe Gerry", every time Adams denies being in the IRA or seems to appear to cover up the crimes of others.
As Fine Gael's Brian Hayes wrote in 2015: "Ms McDonald always asks the hard questions of others…[but] has never asked a hard question of the man she sits beside every week in the Dail.
"Why does accountability just apply to some?"
She'll be at it again with the Garda Commissioner - and though I'm no fan of Noirin O'Sullivan, compared to McDonald she's a model of rightness and frankness and I've love to see her wipe that sanctimonious smirk off her persecutor's face.