It was his fourth in five progressive years as Kildare manager but by far the most comprehensive and, by extension, probably the most damaging.
He was down, visibly dejected but also reflective and philosophical.
The defeat by Cork, coming in year five and at a time when Kildare were expected to bridge previous shortfalls, looked like the last gasps of a drowning team but McGeeney was peering into the future as much as gazing regretfully at the very recent past and it now seems close to certain he will be back as Kildare manager.
The facts are this: McGeeney has a year left on his most recent agreement with the county board, hence no formal ratification process is required for him continue. Secondly, there seems to be little appetite within the halls of power for change, such is the esteem in which he is held, as is the recognition of the progress under his management.
And McGeeney himself, as county board chairman John McMahon told the Herald, "is not a quitter".
"Kieran has to make his own mind up first and there is a consultation process there with the management team, the players and the board," McMahon insisted. "There is most definitely not any rush to get things sorted. We need to give people time to digest the result. The result was the result and it was a huge shock to everybody but we will all take a bit of time."
Two recent managerial appointments probably cast-ironed McGeeney's position even before Sunday's setback. Firstly, Glenn Ryan's reinstatement as Longford boss for another year took, for the moment at least, the most obvious other contender for the Kildare position out of the loop.
And from McGeeney's own point of view, many in Armagh see his homecoming as something of an inevitability, even if he has never made any particularly loud noises in that regard himself.
But the ratification of his former assistant Paul Grimley in the Orchard County removes that possibility for at least a couple of years. So where next for 'Geezer' and Kildare?
McGeeney intimated that a few players would probably go of their own accord. Johnny Doyle, Dermot Earley and Ronan Sweeney seem, by virtue of their age, the most likely candidates.
"In the last number of years, we have gone from nobodies to contenders," said a dejected Doyle to local radio station KFM afterwards. "And it might take something different ... there are a lot of young lads coming on there and there will be three of four who no one will expect to kick it on and get it over the line."
He stopped just shy of retiring there and then, but twice insisted: "It was a pleasure to be part of that team," adding, "it definitely is a young man's game and unfortunately, I'm not getting any younger. Who knows what the year will bring. There will be a lot of changes, I'm sure.
"A lot of players give it five or six years and then they quit," McGeeney said, harking back to his own playing days with Armagh. "But seven or eight of us kept knocking at the door.
"It took us 10 years. You thought you'd made the breakthrough when the likes of Stevie (McDonnell) and that came through on the team, next thing it didn't, then Ronan Clarke, three years later, next thing fellas are touching their 30s."
Eamon Callaghan and James Kavanagh have given a decade of service each and may also consider their positions but outside of that, the group is quite young. A re-think, both tactically and with regard to personnel, is inevitable, however.
Eoin Doyle, for instance, was a revelation this year. Ollie Lyons' form faded as the season went on and Peter Kelly never found them same levels as his All Star season of 2010 but both have youth, time and talent on their side.
Tommy Moolick, Pádraig Fogarty, Fionn Dowling all have top level experience and soon enough, so too should Paddy Brophy, David Hyland and, depending on his soccer career with Bohemians, possibly even Kevin Feely.
Plenty of Kildare eyes will also be on former minor sensation Paul Cribben, now in the final year of his contract with Aussie Rules outfit Collingwood and no closer to making the breakthrough with one of the AFL's best teams.
There is a financial element to the equation too, though. Kildare's books are in dire straits and now out of the control of the board themselves. The cost of preparing a team is rising and Kildare's costs must, by necessity, fall and it will be interesting to see how McGeeney would take being directed to scale back on such necessary expenses, especially after a season when the top teams have put distance between themselves and the Lilies.
Yet asked whether it was possible to turn a dozen-point defeat by Cork into a title-threatening side in just a few short months, he was stoic.
"It's possible. You look at Donegal, they were beaten by 18 points by Armagh one year and have come back the next two years so it is possible."
No announcement is expected in the short term but McMahon was adamant: "We're not talking about months here, we're talking about weeks," adding with authority: "but Kieran McGeeney is not a quitter."