Short answer, read:
marxists.org/archive/bordiga/works/1926/comintern.htm
It's pretty short, it's just a speech. But the most relevant section I will copy pasta into another post (which is about half of the article anyway).
Right off the bat, I'm going to say that none of this is going to be of any interest to those who deny that the comintern became dominated by the russian party (and was much from the beginning, although not to nearly the same extent). Those engaged in Stalinist apologetics (e.g. Grover Furr) and who are only interested in historical revisionism and denial of facts are not going to get anything out of this discussion, much like how no one else will get anything out of what they say beyond some entertainment from extreme mental gymnastics.
Also this was the point where Bordiga called Stalin the "gravedigger of the revolution" to his face - the last person to do so and live. This was done after Bordiga proposed that, to show the internationalism of the workers' struggle, that all the communist parties of the world should rule Russia together.
No he didn't. He went against much of the rest of the Italian Communist Left in his denial of Russia's state capitalism for so long.
Unlike the councilists, Bordiga's problem was not democracy fetishism (as any cursory glance at any of his writings should make obvious, see The Democratic Principle marxists.org/archive/bordiga/works/1922/democratic-principle.htm [his problem was his retreat into metaphysics of the party {party's inversion of praxis, yada yada yada}]). In fact he was pretty explicit that the soviets must arise from the party.
"If the bourgeois class is still in power, even if it were possible to summon proletarian electors to nominate their delegates (for there is no question of using the trade unions or existing internal commissions for the purpose), one would simply be giving a formal imitation of a future activity, an imitation devoid of its fundamental revolutionary character. Those who can represent the proletariat today, before it takes power tomorrow, are workers who are conscious of this historical eventuality; in other words, the workers who are members of the Communist Party.
In its struggle against bourgeois power, the proletariat is represented by its class party, even if this consists of no more than an audacious minority. The Soviets of tomorrow must arise from the local branches or the Communist Party. It is these which will be able to call on elements who, as soon as the revolution is victorious, will be proposed as candidates before the proletarian electoral masses to set up the Councils of local worker delegates." marxists.org/archive/bordiga/works/1919/soviets.htm
(I did the bold but the italics are his own)
At first he thought it was tending towards capitalism, that it had in some sense begun the transition towards socialism, and was going backwards, and at the same time building a very young capitalism. But to him this was less important (as different situations could require temporary retreats economically) compared to the degeneration politically. It was that the russian state had ceased to work in the service of the revolution which cemented its counter-revolutionary nature and made the retreat economically relevant.
It took even longer before he started accepting any idea of "state capitalism" in the sense that leftcoms use it.
What your phrasing did get correct however was the de-emphasis on the "state" in "state capitalism", when he did come towards accepting it. Bordiga focused much more on agriculture (this being somewhat connected to his upbringing).
Bordiga often denied that there was anything particular "statist" about Russian capitalism, (often flip-flopping between that and that there is nothing to be unexpected about the large state involvement in Russian capitalism put in historical context [theorizing about late feudal Russia being a sort of "state feudalism" as he called it])
But Bordiga never had any particular problem with the idea of party dictatorship or lack of democracy as counter-revolutionary in themselves.