1. That they were martyrs for the gospel
2. That they failed to listen to sound council of the leadership and were killed as a consequence.
Here is my original remarks on this as well as some expansion.
In the view of some of the research I have done on this, while nowhere near as extensive as David I think it is still significant to the conversation.
Much of the early church period is millenial in nature until the expulsion at Missouri. After that there is pressure on Joseph over the Missouri arrest which causes him to be on the run for a part of the Nauvoo period. I am sure that as this constant pressure kept up to bring Joseph to Missouri Justice and then his Martyrdom after must have made Haun’s Mill all the more important to the Saints.
The Millenial idealism would have seen sacrifice and struggle as a part of bringing about the new millenial era. Fellows like Sidney Rigdon liked to claim they would be wading in Gentile blood so the idea of fighting and defending your religion was a part of the talk of the Saints.
Four years later Joseph is under a different kind of pressure. He is seeing trusted fellow leaders abandon the church and seemingly taking the time after to hamper the church. While I think in the context of the situation in 1842 Joseph’s admonition had bearing on the events he was going through. Like so many other things in Joseph’s life the hear and now were types of past events. In this case I think this was during the Bennett era when members of the church, like Orson Pratt were not listening to sound council.
Here he uses the Haun’s Mill example of the worst case senario for not listening to sound council. For Joseph your failure to follow the prophet can lead to very bad things for you. But this is not saying that the people of Haun’s Mill were not victims. Or that they did not sacrifice themselves defending their religious beliefs.
Taken in that view I think there is nothing wrong with considering those killed at Haun’s Mill as Martyrs, they died for the testimony of Jesus and the restored Gospel. While making a bad decision to stay there are many accounts of disiples failing does not make them less qualified in my view.