Textual: Mormon’s clear sympathies for the Nephite church are manifest here. The Nephite churchmen were persecuted, and while (in general) they obeyed the command to avoid persecutions of the non-members, there were still some who lost their tempers and retaliated against the persecutions heaped upon them.
Humans being who humans are, we find it none too surprising that some who were persecuted should fight back. The point here is not human nature, but the nature of Mormon’s editing. When Mormon enters this information, it is couched in such a way that the blame lies with the non-churchmen rather than the churchmen. Mormon makes sure that we understand that it was a retaliation, not an initiation of persecution. There is too little information to know precisely what was on the original plates. Mormon could be reading accounts of actions, and making his own interpretation. It is also possible that the originals also had sympathy for the churchmen, as the records were being kept by churchmen.
Regardless of the nature of the original, Mormon chooses to present this information, and presents it in a certain way. This is not the stuff of raw data, but rather the conclusion of one who has analyzed the situation for us. What the very specific actions might have been, we cannot know. We know that persecutions led to fistfights, but we do not know from this information if fists were equal retaliation or excessive retaliation. Because of Mormon’s editing, we presume the best of the Nephites. In a very similar way, most LDS accounts of persecutions place the LDS in the blameless position, even when they were pressed by circumstances into retaliation. It is quite possible that, just as with the LDS history, there were times when the churchmen were not entirely excusable.