Journalists warned not to take either selfies with Irish players or seek autographs
Such a warm night to receive a cold shoulder. Everyone was feeling the heat on another broiling hot day except, it seemed, the unflappable manager.
Perhaps his now familiar embrace of eccentricity, rather than anything more suspiciously malevolent, made him deign to invest quite the element of slapdash and farce to the announcement of his Euro 2016 squad.
Especially given that the mythical midnight deadline, it is quite clear, is not really worth the paper it is written on - especially since the man who signed off the tournament regulations, Michel Platini, is now banned from all football activities.
O'Neill can still alter his squad until a day before the Sweden opener due to injury; we understood just why last evening - and it wasn't just because of the dire performance from his second-string. We knew they would be hopeful; not hopeless.
Earlier, as the players completed their oxymoronic warm-up in the still beating sun, one of their colleagues had already succumbed to a twist of fate; Harry Arter felled with a thigh muscle injury.
In fairness, he might have bargained on bringing two prospective crocks - James McCarthy and Robbie Keane - a third would invite Wildean comment.
O'Neill, despite what he will say, had probably already committed his roster to the online UEFA portal, leaving merely minute tinkering to be added last evening. And yet there was farce aplenty; journalists were apparently warned not to take either selfies with the players or seek autographs as they were working in a professional environment.
A professional environment, it should be added, which meant most operated without desks, Wi-Fi or power points. First-world problems, perhaps, but third-world administration. We did get Tayto and ham sangers at the break, though . . .
Meanwhile, the deadline loomed even if the evening's starters seemed as if the only looming deadline in their lives was an impending holiday. It made one wonder if there was a case for bringing 20 players instead.
And, we wondered, how serious was this deadline business anyway?
In the interests of indefatigable investigative journalism, we decided to, well, investigate, by ringing a nice lady in UEFA head office.
Regulation 44.02 of UEFA's 58-page tournament regulations - it was really too hot to stay in the sun yesterday so one chose research over relaxation - outlines quite clearly the process.
Our woman shuffles away from the phone towards, we presumed, a heaving collection of dusty files and manuals in the Nyon offices. "Well," she informs the Irish Independent after breathlessly returning, "it has never actually happened before so we would probably communicate something afterwards."
And, erm, that was it. So after all the staking of claims, minding of strains and twinges and hammers, the Sword of Damocles is not exactly being wielded with frightening force.
At the end of the day there is no end of the day.
O'Neill's attempts to frantically amend Auto-Correct on his phone - Harsh Arse making the squad instead of Harry Arter, and so on - would be unpunished.
Could Ireland be evicted from a European Championship before a ball was kicked?
Expulsion for starting a war is fair enough but a bounced email would be a tad embarrassing.
O'Neill, one senses, is a devotee of the old aphorism about never putting off until tomorrow what you can put off until the day after tomorrow; he once selected five goalkeepers for a squad, if memory serves.
Keiren Westwood's surprise return to the fold, particularly given the (unspoken) whiff of personality issues between the pair, added fresh intrigue. So did his absence from this one.
And so we watched as O'Neill trudged off to find a quiet corner in Turner's Cross - there were few, perhaps he chose a toilet cubicle - to put his arm around the shoulders of the rejected.
For them, the sense of a deadline probably seemed all too real. For the chosen 23, it is like a lifeline.