(I appreciate that I said "exploit the uncertainty" but I meant more the sort of news media confusion, unclear facts on the ground sort of uncertainty -- fast moving events)
Firstly: the Capitol violence wasn't a coup (or putsch) in and of itself. They had no organised plans to seize direct power. It was an armed mob assault, and everyone there knew what their job was: to stop the count. Some of them even went home when they realised they'd achieved it.
Second: it wasn't really stochastic in an important sense.
Stochastic terrorism is what I understand you to be alluding to by analogy. That is usually considered to be e.g. regular lone-wolf or small attacks that are implicitly encouraged by not being condemned. There is no organising thread or support network (unlike e.g. Al Qaeda and the Taliban).
The people encouraging that stuff don't know what specific outcomes there will be to exploit, but they have reason to suspect an increase in exploitable outcomes and they do nothing to stop it (or better, they are sort of notably half-hearted and equivocal in stopping it).
But in this case, the rally was long-planned and there was plenty of evidence online about who it was attracting. And all the other threads in the autogolpe I mentioned are planned and organised by a small group of people. This is widely understood -- the challenge is proving it in a court.
And it's not "stochastic" if you stand in front of that known crowd of people who have turned up to "stop the steal", and you tell them to "fight like hell". There's no defence that it is metaphorical, especially given everything we know he'd been advised. He (repeatedly) tried to get armed supporters allowed into the main crowd. "They're not here to hurt me!"
Almost nobody stands up in front of a mob and issues direct, unambiguous commands. You do that with a team or an army. Not with a mob. That's not the true power of that situation. You stand up in front of a mob, you use dogwhistles and the mob does what you want. Because that means you can try plausible deniability, which might keep you personally out of jail to do it all over again.
Trump is disordered but he is cunning; he knew he had an armed crowd out there, and he riled them up. And Giuliani literally has form for inciting a riot (of police officers!) so he knew what was going to happen too. They had to have an idea what the specific immediate time-sensitive outcome would be, and it is one they desired. That is not "stochastic". It's directed.
(Edited considerably, haven't had coffee yet)