I think there is a very good chance this is true, but it also paints the picture of the board being incompetent and incapable of confrontation. They could have filed formal complaints, mandated increased scrutiny, handed off Sam's responsibilities to other people, or threatened legal action. Instead, they attempted a secret coup, which of course makes Sam look like the underdog
I've seen the "coup" framing a lot I just don't see how that's justified. They're the board of directors! Hiring and firing the CEO is core to the job (as is maintaining mission alignment, in the nonprofit world).
It isn't justified, it's just misleading propaganda. Unfortunately through repetition and the enthusiasms of various fandoms, it's gotten lodged in the public mind.