Even as late as yesterday afternoon, the Scotsman published an article stating the appointment of the 42-year-old was imminent—yet by the evening news it had emerged that was, in fact, not the case.
Several outlets reported Keane had asked not to be considered for the job in order to stay on as assistant manager to former Celts boss Martin O'Neill with the Irish national side.
The Irish Independent suggested the idea of job sharing (something he already does with his work as a television pundit for ITV) had been floated and, presumably, rejected by Celtic. The Independent did, however, assume that would lead to Keane leaving Ireland rather than declining the Parkhead hotseat.
Pundits, commentators and ex-pros all took to Twitter in reaction, with former Celtic striker John Hartson perhaps summing it up best from Celtic's point of view:
Similarly, many of Keane's critics pointed to a so-far mediocre managerial career as evidence that, however big his name, success outside of the league was not guaranteed.
Spiers's Herald Scotland colleague, Graeme Macpherson, referenced Keane's long-time boss Alex Ferguson as a lofty critic of the Irishman's coaching credentials.
Ferguson wrote in his recent autobiography that Keane's "impatience" meant he was likely to always look for a quick-fix and spend money, rather than try to build a team—an option which would have been fairly limited to him at Celtic.
Of course that is simply an opinion and comes from a manager who had funds at his disposal Keane could only dream of when he was boss at Sunderland and Ipswich, as Macpherson pointed out in his article.
However, the real question just may be this: Would taking the Celtic job have furthered his career prospects?
For, surely, Keane wants a return to the Premier League when he does decide to take on a full-time managerial role. Indeed, The Guardian report today that he is in talks to become assistant to Paul Lambert at Aston Villa.
And the track record of previous Celtic managers tells a damning story.
Never has a Celtic boss, however successful they were with the club, gone on and directly won themselves a job at an elite English club.
Keane's ITV colleague and former Celts boss Gordon Strachan is testament to that himself.
Having left Glasgow after four years with three consecutive league titles, two League Cups, a Scottish Cup and two trips to the last 16 of the Champions League on his CV, his next job was with Middlesbrough in the English Championship.
It remains to be seen which club Neil Lennon will opt for, but it is highly unlikely to be a club anywhere near the size or stature of the one he has just departed.
Moreover, Keane has expressed his contentment with his current role as an assistant—something which often evolves into a full manager's job in the future:
People keep asking me about other jobs. In my quiet moments, I obviously want to go back to being a manager. But I have got a job and I am very happy in my job. I am really appreciating the opportunity I have at the moment.
Former West Bromwhich Albion boss Steve Clarke has assumed Keane's position as favourite to land the Hoops job, with Malky Mackay and Owen Coyle further back in the field, according to Oddschecker.
Despite this, chief executive Peter Lawwell told STV only last week that the club had drawn up a shortlist of "between five and 10" candidates to replace Lennon, so it is possible people like Jackie McNamara, Henrik Larsson and David Moyes are still in the running as well.
Whoever is chosen, time is of the essence for Celtic.
The club simply cannot afford to procrastinate before appointing Lennon's successor. So much of their 2014-15 season hinges on qualifying for the Champions League group stages—the quest for which begins in the second qualifying round on 15 July.
With the fortunes of the club of paramount importance, Keane's decision, whether right or wrong, must take a back seat as soon as possible.