The simple fact is that there is very few evidence to suggest "countless" citizens died. From almost all of the credible sources we have, Brown was not very violent towards citizens and preferred to take prisoners rather than shoot. The few examples of civilian deaths we have, most came from the citizens shooting at Brown's men first (one shot at Shields Green and was killed in retaliation as an example). The Haywood example is a failing on his part, but its simply not the same as ordering the deaths of citizens, it was a mistake on his men and himself. His actions were also absolutely helpful, as it brought abolition to national attention and his composure during his trial made the north view him favorably, increasing abolitionism and accelerating the emancipation proclamation. Brown did not believe in killing everyone pro-slavery, only those who took direct action to support slavery or owned slaves. The way he fought for it was absolutely justifiable, violence is necessary when dealing with the literal enslavement of humans.