I have been musing about how this could have come about in practice?
Joseph F Smith talked about three threats to the church from within. They were the flattery of prominent men in the world, false educational ideas, and the one he said is the most serious threat from within, sexual impurity.
Were one or more of these at the root of what happened here? Because falling apart from within is what happened. The Nephite government was overthrown by a secret combination made up of a group of men that sounds like it included almost all the high priests in the church. Not so much the Elders or other priesthood offices, from what is described.
3 Nephi 6:20 And there began to be men inspired from heaven and sent forth, standing among the people in all the land, preaching and testifying boldly of the sins and iniquities of the people, and testifying unto them concerning the redemption which the Lord would make for his people, or in other words, the resurrection of Christ; and they did testify boldly of his death and sufferings.
21 Now there were many of the people who were exceedingly angry because of those who testified of these things; and those who were angry were chiefly the chief judges, and they who had been high priests and lawyers; yea, all those who were lawyers were angry with those who testified of these things.
22 Now there was no lawyer nor judge nor high priest that could have power to condemn any one to death save their condemnation was signed by the governor of the land.
23 Now there were many of those who testified of the things pertaining to Christ who testified boldly, who were taken and put to death secretly by the judges, that the knowledge of their death came not unto the governor of the land until after their death.
24 Now behold, this was contrary to the laws of the land, that any man should be put to death except they had power from the governor of the land—
25 Therefore a complaint came up unto the land of Zarahemla, to the governor of the land, against these judges who had condemned the prophets of the Lord unto death, not according to the law.
26 Now it came to pass that they were taken and brought up before the judge, to be judged of the crime which they had done, according to the law which had been given by the people.
27 Now it came to pass that those judges had many friends and kindreds; and the remainder, yea, even almost all the lawyers and the high priests, did gather themselves together, and unite with the kindreds of those judges who were to be tried according to the law.
28 And they did enter into a covenant one with another, yea, even into that covenant which was given by them of old, which covenant was given and administered by the devil, to combine against all righteousness.