Several things were happening that night unbeknownst to many.
Yes, there was the fact that the Queen of Hearts and the King of Spades were discussing 'business matters' in the garden of the castle and away from the crowd. Or perchance the occurrence of the Knight of the Queen dragging Alice back to her room—or rather that of the Lord Lockhart's.
Perhaps one's happening was focused on the three men that had gathered up in the Queen of Hearts' personal chambers and were discussing heatedly over a matter. Or maybe it was just the King of Hearts left alone in the court hall once again and questioning the futility of everything.
But that wasn't just it either.
A great number of the Nobility were relieved at the end of the trial of the Joker where everyone of them had survived it.