Literally declaring yourself the winner of an election that you solidly lost and then repeating that claim over and over again as your supporters rile themselves up and prepare for violence abso-fucking-lutely qualifies. If the election really was stolen (it wasn't), then violence on a grand scale would be more than justified (it's not), so pushing a false claim to that effect when you have as much power to make it stick is one of the most directly violent acts that can be committed.

"This election was stolen" is way more dangerous than "Fire!" in a crowded theater because if the bullshit sticks then you actually end up with war.