Forget any distinction between resigning and being sacked. Had Nick Smith not fallen on his sword yesterday, one would have fallen on him fairly promptly.
He had to go. He had to go because he has been silly or misguided or both in ignoring conflict of interest rules which apply to Cabinet ministers.
But he also had to go because John Key desperately needed to bring some closure to this untidy, unseemly episode and its cast of high-profile National Party figures and highly-explosive allegations.
The public may not know every last detail of the saga. But they will have seen enough for Winston Peters' categorisation of the goings-on as National Party "cronyism and sleaze" to start to find a ready audience.
Such foot-in-mouth follies erode public confidence in a government. Key's and National's poll ratings are not so crash-hot that they give him and his colleagues unlimited latitude for mistakes.