if this was the case it would explain why he can’t give the real reason for the firing: because saying it out loud would put him in severe legal Jeopardy.
I don't think it matters anymore. He's between a rock and a hard place: if the others followed him without knowing the real reason he's got two more enemies on the board who are likely talking to their own lawyers by now. If he spills it he's screwed immediately, if he doesn't he's screwed in the longer term. So for his sake I hope there are some nice time-stamped minutes that detail exactly what caused them to act like they did and it had better be good.
That’s another thing though: they were apparently holding secret meetings plotting all this without informing Greg or Sam, which is apparently against their own regulations. So if that’s the case it’s unlikely there is any formal record of what was discussed. And perhaps by design.