Merely fifteen minutes following the club released the announcement of their manager's shock departure via a perfunctory five-paragraph communication, the howitzer arrived, courtesy of Dermot Desmond, with clear signs in obvious fury.
In an extensive statement, key investor Desmond savaged his former ally.
This individual he persuaded to join the club when Rangers were getting uppity in that period and required being in their place. And the figure he once more turned to after the previous manager left for another club in the recent offseason.
Such was the ferocity of his critique, the jaw-dropping comeback of the former boss was almost an after-thought.
Two decades after his exit from the organization, and after a large part of his latter years was given over to an continuous series of appearances and the performance of all his old hits at Celtic, O'Neill is returned in the manager's seat.
Currently - and maybe for a while. Based on things he has said lately, he has been eager to secure a new position. He'll see this role as the perfect opportunity, a present from the club's legacy, a homecoming to the environment where he enjoyed such glory and adulation.
Will he give it up readily? It seems unlikely. The club could possibly reach out to contact their ex-manager, but the new appointment will serve as a soothing presence for the moment.
The new manager's return - however strange as it is - can be set aside because the most significant 'wow!' moment was the brutal way the shareholder wrote of Rodgers.
This constituted a full-blooded endeavor at defamation, a labeling of Rodgers as deceitful, a source of untruths, a disseminator of misinformation; disruptive, misleading and unacceptable. "A single person's desire for self-preservation at the expense of others," stated he.
For a person who values decorum and places great store in business being done with confidentiality, if not outright secrecy, here was a further illustration of how abnormal things have become at the club.
Desmond, the organization's most powerful presence, operates in the background. The absentee totem, the one with the authority to take all the important decisions he pleases without having the responsibility of justifying them in any public forum.
He does not attend club annual meetings, dispatching his son, his son, in his place. He rarely, if ever, does interviews about the team unless they're glowing in tone. And even then, he's slow to communicate.
He has been known on an occasion or two to support the organization with confidential messages to news outlets, but nothing is made in public.
It's exactly how he's preferred it to be. And it's just what he went against when going full thermonuclear on the manager on Monday.
The official line from the team is that Rodgers stepped down, but reading his criticism, carefully, you have to wonder why did he permit it to get this far down the line?
Assuming the manager is guilty of every one of the things that the shareholder is alleging he's guilty of, then it's fair to inquire why had been the manager not removed?
He has accused him of spinning information in open forums that did not tally with reality.
He says his words "played a part to a toxic environment around the club and encouraged animosity towards individuals of the management and the board. Some of the criticism aimed at them, and at their families, has been completely unjustified and improper."
Such an extraordinary charge, that is. Legal representatives might be mobilising as we discuss.
To return to better days, they were tight, the two men. The manager lauded the shareholder at every turn, expressed gratitude to him every chance. Brendan respected him and, really, to nobody else.
It was Desmond who drew the heat when Rodgers' returned happened, post-Postecoglou.
This marked the most controversial hiring, the return of the returning hero for some supporters or, as other Celtic fans would have described it, the arrival of the shameless one, who left them in the lurch for another club.
The shareholder had Rodgers' support. Gradually, Rodgers employed the charm, achieved the victories and the trophies, and an uneasy truce with the supporters became a affectionate relationship once more.
It was inevitable - always - going to be a moment when his ambition clashed with the club's business model, however.
This occurred in his initial tenure and it happened again, with added intensity, recently. Rodgers spoke openly about the sluggish way the team went about their transfer business, the interminable waiting for targets to be secured, then not landed, as was frequently the case as far as he was concerned.
Time and again he stated about the need for what he called "agility" in the transfer window. The fans agreed with him.
Even when the club splurged record amounts of funds in a calendar year on the expensive Arne Engels, the £9m another player and the £6m Auston Trusty - none of whom have cut it to date, with Idah already having left - Rodgers demanded increased resources and, often, he did it in openly.
He planted a controversy about a lack of cohesion within the team and then walked away. Upon questioning about his comments at his subsequent media briefing he would typically downplay it and almost reverse what he stated.
Lack of cohesion? Not at all, all are united, he'd say. It appeared like Rodgers was playing a dangerous game.
A few months back there was a report in a newspaper that allegedly originated from a source associated with the club. It said that Rodgers was harming Celtic with his open criticisms and that his true aim was managing his departure plan.
He desired not to be there and he was arranging his exit, that was the implication of the article.
Supporters were angered. They then viewed him as similar to a sacrificial figure who might be carried out on his shield because his directors did not back his plans to bring success.
This disclosure was damaging, naturally, and it was intended to harm Rodgers, which it did. He demanded for an inquiry and for the responsible individual to be dismissed. Whether there was a probe then we learned nothing further about it.
At that point it was clear the manager was shedding the support of the people in charge.
The regular {gripes