nah, probably some toxic sex stuff. i can't think of any business reason for sam to be ousted. bribes, losing money, lies to the board? all good and well as long as the company stays the leader in the absolute most groundbreaking tech in human history so far.
So this is the non profit board. Maybe he was trying to influence the board members to make OpenAI a for profit company and the board saw that as a traitor move.
The only other business thing I could think of is he moving openAI's money to one of his other venture or for some other personal gain.
I don't think spending too much money in openAI could get him fired like this in current environment. Neither does overpromising stuff or something.