I'm assuming from the above that you have info from someone at the club?
As to the first bit, Poyet was unable start his job at Sunderland until legal proceedings were out of the way with BHA. No more or less mysterious than that.
It's entirely different as the board knew sacking a manager as popular as Poyet out of the blue would be a massively unpopular decision. Voila! "Gross Misconduct". Sorted.