Or alternately, he made a well-reasoned and principled decision by getting rid of Sam, but now everyone thinks he's awful for it and he's trying to save face and avoid ruining his own career
Or a secret third thing, of course
If the board had just found out about this, it would totally check all the boxes. Making something that could be destabilizing for the ecosystem or compete with OAI's partners, something which is arguably within scope of OAI itself yet he's raising funds as a venture he wholly controls while using time and possibly resources of OAI in the process (self-dealing?), etc.
It's enough of a gray area that all those things would be above board (hah!) if he had notified them and kept them in the loop, but a fireable offense if he hadn't.