His last sentence is the main hint. Disagreement over dangers of AGI discoveries and how to handle I’d guess.
They could have waited another 30 mins for the markets to close before making the move. This isn’t the culmination of a long-standing problem.
Looking at the people on the current board, it doesn't seem they have a lot of experience being independent board members in large public corporations.
No non-profit has this level of public scrutiny, It could just be that they were sloppy because they are not professional board members.