Title here is misleading (probably deliberate). The email that got this person “fired” was one that allegedly contained an ultimatum and a threat to resign. The employer then called her bluff and accepted her resignation with immediate effect.
Even if it were the case, responding to "retract this paper" with "No; I prefer to resign" is/should be par for the course for a researcher.
They set themselves up for failure regardless of the paper's content.