Merely fifteen minutes following the club issued the news of their manager's surprising departure via a perfunctory short communication, the howitzer landed, courtesy of Dermot Desmond, with clear signs in apparent fury.
Through 551-words, key investor Desmond savaged his old chum.
The man he persuaded to join the team when their rivals were gaining ground in 2016 and required being back in a box. And the figure he again turned to after the previous manager departed to another club in the summer of 2023.
So intense was the ferocity of Desmond's critique, the jaw-dropping return of the former boss was practically an secondary note.
Twenty years after his departure from the club, and after much of his latter years was given over to an unending circuit of public speaking engagements and the performance of all his past successes at Celtic, O'Neill is returned in the dugout.
For now - and perhaps for a while. Based on comments he has expressed recently, O'Neill has been keen to secure another job. He will see this one as the perfect opportunity, a present from the Celtic Gods, a homecoming to the environment where he enjoyed such glory and adulation.
Would he relinquish it easily? It seems unlikely. The club could possibly make a call to sound out Postecoglou, but the new appointment will serve as a balm for the moment.
The new manager's reappearance - as surreal as it is - can be set aside because the biggest shocking moment was the harsh way the shareholder wrote of the former manager.
This constituted a full-blooded endeavor at defamation, a labeling of him as deceitful, a perpetrator of falsehoods, a spreader of misinformation; disruptive, misleading and unjustifiable. "One individual's wish for self-interest at the expense of others," wrote Desmond.
For somebody who prizes decorum and places great store in dealings being done with discretion, if not complete privacy, here was another example of how abnormal things have become at Celtic.
Desmond, the organization's most powerful presence, moves in the margins. The remote leader, the one with the authority to take all the important decisions he wants without having the obligation of explaining them in any open setting.
He does not participate in team AGMs, dispatching his son, his son, in his place. He rarely, if ever, gives media talks about Celtic unless they're hagiographic in tone. And even then, he's reluctant to speak out.
There have been instances on an rare moment to defend the club with private missives to news outlets, but nothing is heard in the open.
This is precisely how he's wanted it to remain. And it's exactly what he went against when launching all-out attack on Rodgers on Monday.
The directive from the team is that Rodgers resigned, but reviewing his invective, line by line, one must question why he allow it to reach this far down the line?
If the manager is guilty of all of the things that Desmond is claiming he's responsible for, then it is reasonable to ask why had been the coach not dismissed?
He has charged him of distorting information in open forums that were inconsistent with reality.
He says Rodgers' words "played a part to a toxic atmosphere around the team and fuelled animosity towards members of the executive team and the directors. Some of the abuse directed at them, and at their loved ones, has been entirely unjustified and unacceptable."
Such an remarkable charge, indeed. Legal representatives might be preparing as we speak.
Looking back to better days, they were tight, the two men. The manager lauded Desmond at all opportunities, expressed gratitude to him whenever possible. Rodgers respected Dermot and, truly, to nobody else.
It was the figure who took the criticism when Rodgers' comeback happened, post-Postecoglou.
This marked the most controversial appointment, the reappearance of the returning hero for a few or, as some other supporters would have put it, the return of the shameless one, who departed in the lurch for Leicester.
Desmond had his back. Over time, the manager turned on the persuasion, delivered the victories and the trophies, and an uneasy peace with the fans turned into a love-in once more.
It was inevitable - consistently - going to be a moment when Rodgers' goals came in contact with the club's operational approach, however.
This occurred in his first incarnation and it happened once more, with bells on, recently. He spoke openly about the sluggish process Celtic went about their transfer business, the interminable waiting for targets to be landed, then not landed, as was too often the case as far as he was believed.
Time and again he spoke about the need for what he termed "flexibility" in the market. The fans agreed with him.
Even when the organization spent record amounts of funds in a twelve-month period on the expensive one signing, the costly another player and the £6m Auston Trusty - all of whom have cut it so far, with Idah since having departed - Rodgers demanded more and more and, often, he expressed this in public.
He set a controversy about a lack of cohesion within the team and then distanced himself. When asked about his remarks at his next news conference he would usually minimize it and nearly reverse what he said.
Internal issues? No, no, all are united, he'd claim. It looked like he was playing a dangerous strategy.
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 public outbursts and that his true aim was orchestrating his exit strategy.
He didn't want to be there and he was engineering his exit, that was the implication of the article.
Supporters were angered. They now saw him as similar to a sacrificial figure who might be removed on his honor because his board members wouldn't back his vision to bring success.
The leak was poisonous, of course, and it was intended to harm him, which it did. He called for an inquiry and for the guilty person to be removed. Whether there was a probe then we learned nothing further about it.
At that point it was plain Rodgers was shedding the support of the people in charge.
The regular {gripes