There is a concept of a boardroom coup, which is what this was. The lack of decorum, the unceremonious and abrupt exit at the highest levels including removal of the chairman of the board, and the damning statement implying misconduct are very serious and substantial moves for any board to make, nevertheless one of the size of an org like OpenAI. They did not consult with investors, did not attempt to negotiate with the CEO/ask for a resignation, or anything of the sorts to resemble reasonable process. Usually you retain some form of legal counsel before making such a substantial move, but given the traditionally lax oversight non-profits, it doesn't seem like this is the case.
It's only at the abrupt all-hands meeting they called on a Friday night that it became clear that Ilya Sutskever was at the center of it. He had his disagreements, and pushed the board into making such a abrupt move, and then goes on to say something like "oh I agree it wasn't the ideal way to do it". It's very clear this was a power struggle, not maleficence (per words of OpenAI CTO), from Sam Altman. At least so far, it boils down to ... Ilya didn't like feeling sidelined, so he took things over. And now it's clear the board that sided with (or rubber stamped?) Ilya just wasn't prepared for the consequences.