Earlier quoted context omitted.
The process, as told by the author, was that one of the editors invited to submit, and three weeks later it was published upon which the rest of the editorial board took notice and threatened resignation. By that telling it was published practically on the spot, especially for mathematics where things are famously glacially slow. Browsing through the journal one mostly sees submission and publication dates separated…
According to the article, publication was approved by Editor-In-Chief Mark Steinberger, who founded the magazine 25 years ago. The members of the editorial board did not just threaten resignation, but (according to the article) threatened to "harass the journal until it died."
As for the description of alleged emotional states involved, I'm oblivious and not seeing the relevance. Recounting the events and actions taken sufficed for a horrific story. The author deemed it important however to make it into something even more colourful with threats of some unspecified future actions (how does one harass a journal?).
The managing editor you speak of went on leave and has an interim replacement. I can see that entirely appropriate if only because of how retraction was handled by deletion and overwriting, instead of a proper notice in place. This was extremely unprofessional administration, which is usually a duty of the managing editor solely. The other possibility I described is that it wasn't really published the usual way, which is even more damning.