You may well think that the structure of the company and how the votes on the board work etc means that any motion you can carry at the board is within the sphere of things you can achieve i.e. that you have autonomy to do anything you can secure the votes for, but that's rarely the case. In actual practise people like the investors and other stakeholders can change the rules if they need to, exercise soft pressure, bring legal suits and do other things. Your autonomy to act is effectively pretty narrow.
However this finally plays out, whether Sam comes back or not, whether openAI's board changes, the people who orchestrated this have seriously damaged themselves and they will most likely have less of both authority and autonomy in future.