After Ireland failed to get an away goal in Copenhagen, there was always a live possibility that the Danes would score in Dublin and the home side would end up having to chase the game, the resulting mad pursuit of one of those grandstand finishes against the backdrop of an Aviva in full cry, coming with all the risks of a deflating and decisive concession such an all or nothing gambit invariably entails.

That, for sure, would have been hard to take but, even in my most feverish imaginings, I never envisioned this Irish team, under O’Neill, saving its worst for last and shipping five goals on home soil.

In truth, I don’t believe this result was a grim inevitability, a brutal comeuppance arising naturally out of the manager’s less-is-more football philosophy. Cause and effect on Tuesday night mixed elements of crass individual error, an entirely out of character, all-caution-to-the-wind substitution gamble by O’Neill which totally backfired and last, but by no means least, a master-class in the art of goalscoring from Christian Eriksen.

This was a perfect storm but, in my opinion, a freak one. And I think that’s only fair to acknowledge in the context of the debate about whether Martin O’Neill should now remain at the helm.

The positives of his time in charge are by no means negligible and certainly don’t deserve to be ignored in the atmosphere of gloom and recrimination which has shrouded Irish football since Tuesday night and which, with dreams of summer glory now off the agenda, is destined to make the coming winter seem that bit longer and darker.

It might only heighten the pain to think of the rewarding days and nights the nation enjoyed under O’Neill but they aren’t figments of the imagination.

It’s an impressive highlights reel which includes drawing away to world champions Germany and beating them at home; doing likewise to Bosnia over the two legs of a European Championship play-off; beating Italy, drawing with Sweden and losing narrowly to hosts France at the Euro finals themselves; and beating Austria and Wales away in this World Cup campaign before it all ended in such ignominy on Tuesday night.

Ireland’s generally conservative, low-risk approach under the current management might mean some of those victories came down to the finest of margins, unlikely moments of magic mined from minimal possession and attacking intent — Shane Long’s memorable strike against Germany at the Aviva and James McClean’s winner in Cardiff being two of the most notable examples — but to argue, as some still appear to do, that luck was the biggest factor in achieving all those big results mentioned above, surely stretches credibility to breaking point.

Either that or, since luck appears to play such a decisive part in sporting success at the highest level, we might as well agree to abandon all pretence at logic and just draw the next Irish gaffer’s name out of a big tri-coloured hat.

Of course there have been negatives too, significant ones.

The biggest one is the manager’s generally defensive mindset which has fed into the psyche of the team and seen them surrender possession and points from a position of strength, both on the table and in the course of the action on the pitch itself — the poverty of the football away to Georgia in this campaign being a particularly depressing example.

A related problem has been his failure to utilise to the maximum the talents of our most creative footballer, Wes Hoolahan, a reluctance based largely, it seems, on O’Neill’s misplaced worries about the player’s physicality and stamina in an area of the pitch where the manager seems more concerned with breaking up the play than getting it going.

In terms of doing better with what we have, there is a legitimate argument to be made that we should see more of the mix of fire and finesse Ireland have been able to summon in the more complete performances under O’Neill, such as in Vienna, home and away to Bosnia and at the Euro finals in France.

It can’t be downplayed, however, that the particular case of Hoolahan — a quality footballer in the twilight of his playing career — also serves to shine an unforgiving light on the problem of Ireland’s shallow pool of talent, especially in the critical areas of central midfield and attack.

Jeff Hendrick and Robbie Brady are good players but, if I might borrow a phrase from Martin O’Neill’s fiercest critic, they are not great players. Premier League regulars, yes, but with Burnley not Man City. And for Ireland, they have yet to build consistently on their breakthrough appearances at Euro 2016.

Then there’s James McCarthy who, with his injury woes hardly the sole reason, simply hasn’t lived up to all the early hype.

Up front, meanwhile, the search for the new Robbie Keane goes on and on, a nation now turning a lonely eye to Seanie Maguire and hoping that, when he recovers from his untimely injury, he can go on to fulfil his undoubted talent at the highest level.

It’s only fair to acknowledge too that the injuries suffered by Seamus Coleman and Jon Walters before this World Cup campaign had run its course robbed the team of two of its most inspirational figures and, in the case of Coleman, arguably its single outstanding player.

That Ireland are currently short of the two or three special footballers needed to help turn base metal into gold on a consistent basis seems to me inarguable.

Leicester City’s Premier League title win is widely regarded as the greatest sporting upset of all time but the perception of that team as a collection of wildly over-achieving journeymen neglects to acknowledge that, for their incredible season in the sun, they had a trio of alchemists, Vardy, Mahrez, and Kante, playing to a world-class level.

The main reason Ireland made it through to their last World Cup play-off before this one — and might well have gone on to the 2010 finals but for you-know-who — was that Keane, Duff, and Dunne were still in their prime.

Coleman apart, we haven’t had players of that calibre since, certainly not in the business of creating and scoring goals, although at the other end of the pitch, Shane Duffy is shaping up nicely to be the man to fill Dunne’s big boots over the long haul.

At this low point in our footballing fortunes, it might be worth remembering that the Euros qualifying campaign, which brought us a memorable summer in France, was every bit as much a rollercoaster as this one. It was a campaign in which Ireland took four points from six off the world champions but only one from six against a Scottish team who didn’t even make it to the play-offs. In this World Cup qualification bid, we took four from six against both Wales and Austria, two teams which would have been seen at the outset as our nearest rivals, yet couldn’t maximise the return on those hard-earned away advantages at home.

In the end, the critical difference between the two campaigns came down to how the team fared in one decisive game. And where Ireland were cool and collected in the second leg of the play-off against Bosnia, they were hot and bothered, and ultimately baffled and bewildered, in Tuesday night’s counterpart.

But, devastating as that experience was, I’m not convinced that over the course of two long campaigns, it qualifies as watertight evidence of a manager in terminal decline.

Its closest equivalent in O’Neill’s time was the 3-0 spanking by Belgium at Euro 2016, whereupon the team bounced back to deliver both a performance and a result of real quality, even if it was against a second-string Italian side. Indeed, in three of the four games in France, Ireland played some of their most constructive stuff under O’Neill, this evidence that tournament football could bring out the best in both manager and team now just another reason to regret they won’t get the chance to see if they could repeat the feat at the World Cup in Russia.

Even after Tuesday night, dispassionate contemplation of the bigger picture leaves me still inclined to see the positives outweighing the negatives under O’Neill. And I’m not sure any new manager would be able to wave a wand over the current crop which will guarantee to give people what many seem to believe should be within Ireland’s grasp: A side who can become serial qualifiers playing a brand of football which is both effective and a whole lot easier on the eye. For that to materialise, I suspect the revolution will have to come from the bottom, not the top.

Meantime, if and when a new managerial vacancy does arise, it would be fascinating to see how Chris Hughton or Stephen Kenny would rise to the challenge. But, as things stand, I think O’Neill has done enough to be allowed to make his own mind up about whether he stays or goes.

And if it is to be the latter, he should leave the stage to applause not boos.