How did they structure it to prevent this? Is it in the statutes of the company or smth?
At the top level, there is the non-profit board of directors (i.e.: the ones Sam Altman had that big fight with). They are not beholden to any shareholders and are directly bound by the company charter: https://openai.com/charter
The top-level nonprofit company owns holding companies in partnership with their employees. The purpose of these holding companies is to own a majority of shares in & effectively steer the bottom layer of our diagram.
At the bottom layer, we have the "capped profit" OpenAI Global, LLC (this layer is where Sam Altman lives). This company is beholden to shareholders, but because the majority shareholder is ultimately controlled by a non-profit board, it is effectively beholden to the interests of an entity which is not profit-motivated.
In order to raise capital, the holding company can create new shares, sell existing shares, and conduct private fundraising. As you can see on the diagram, Microsoft owns some of the shares in the bottom company (which they bought in exchange for a gigantic pile of Azure compute credits).
That's not clever or innovative. That's just plain old oligarchy. Intrigue and infighting is a known feature of oligarchies ever since antiquity.
Whether or not it is “clever”, the idea of a non-profit or charity owning a for-profit company isn’t original. Mozilla has been doing it for years. The Guardian (in the UK) adopted that structure in 1936
As for the whole "cleverness" topic... it wasn't designed as an oligarchy, that's merely what it has devolved into. The saying "too clever by half" exists with good reason
Out of curiousity, with the benefit of hindsight; what would you have tried doing differently to prevent such a coup?
I point out this similarity because I suspect that the corporate solution to such "coups" will mirror the government solution: checks and balances. You build a system which functions by virtue of power conflicts rather than trying to prevent them. I won't pretend to know how such a thing could be implemented in practice, however.