Bolsonaro said he'd only act within the Constitution, but never told his supporters to go home nor dispelled claims by his entire activist ecosystem that there was any sort of military intervention in planning. He is, at the very least, morally responsible for what followed as a shepherd who neglected his flock.

The outskirts of military bases in Brasília were still full of frustrated hardliners who'd come from all around the country to rally around their leader. On January 8th they raided and vandalized the empty Congress and Supreme Court buildings. Lula was now vested in the moral authority to clamp down on bolsonarism as rightful self-defense of the State. Remaining bolsonarist encampments demobilized.
All of the January 8th demonstrators, Bolsonaro and several high-ranking officers were indicted for this "coup d'état", or to be more specific, for violently attempting to overthrow the rule of law and the legitimate government (articles 359-L and 359-M of the Criminal Code). Everything from the 2021 remarks against electronic voting machines until the January 8th chimpout was treated as one single attack against democracy.

This is where I speak of a miscarriage of justice. The January 8th vandals/demonstrators/terrorists were certainly wishing for a coup d'état, but no coup was possible from their acts. All they did was trespass and damage public property, which any rowdy demonstration does. They were possibly expecting the president to enforce a state of emergency, which would enable opportunistic military commanders to seize power. But that is at most an incitement to a coup, and in any case, none of that happened.
It takes a great deal of misunderstanding, even deliberate, to see it as a coup. It's like Curtis Yarvin described the logic behind the January 6th "insurrection" in the US:
https://graymirror.substack.com/p/the-great-coup-of-2021
>For example, let’s suppose (I am indebted for this analogy to some Twitter wag, whom I can’t find now) the US Constitution worked like the first-person shooter Halo. If you occupy the center of the Rotunda for more than 90 seconds, you become the Congress. You can pass laws and stuff.
>In this world, occupying the Capitol is indeed a historic threat to the continuity of government. Anyone who makes it past the last bosses to the Rotunda, then can defend the space, has literally interrupted that continuity. In fact, once the circle in the floor turns green, and you can start to legislate, you have technically founded America’s Second Republic. (Or, arguably, like its sixth or something.)
>What about in real life? What happens in real life, when this happens? What happens is: a formal ceremony is delayed for a couple of hours. As if a water main had broken. In the worst-case scenario—they have to use another building. Or even—Zoom. (Maybe Zoom needs a special option that, instead of a room, starts a temple of democracy.)

And this was even less coup-like than January 6th 2021, which did happen when Trump was in power and could in theory do something about it. But the date similarity is deceptive. Lula was in office and Bolsonaro was thousands of kilometers from Brasília and completely powerless.

In one infamous case, a woman was sentenced on coup d'état charges for writing Perdeu, mané ("You lost, jackass") on lipstick over a statue in front of the Supreme Court building. The only weapon found in her possession was lipstick. For reference, Perdeu, mané was what one of the Supreme Court justices had answered to bolsonarists who bothered him over the election results when he was in New York. There's definitively an element of personal vendetta in this case and in the sentences in general. It's less about democracy and more about the physical sanctity of the State against the people.