Got to say, it's almost sad to see such a consumate player like Albus continuing to lose his cool like he has been, almost, but was grateful to see Arthur standing up for himslef like he did, as well as seeing Minerva get her back up for once, rather than her usual brushing things off.
IMO, Dumbledore has overused his rep. He's basing far too many things on a few (educated?) guesses, and very little information. Unfortunately, like most despots, he's decided his way is the only way and won't see any other. As time goes on, he's going to get even more irrational.
Arthur: I've always seen him a sold and dependable man...if a bit eccentric.
Minerva: Once the compulsions Dumbledore placed on her began to fade, she understood what had been done to her, and she was ready to kill. That's why I had Harry convince her to slowly but subtly take over the school and sideline Albie entirely.
When it come's time for that confrontation, she'll have the entire school well in hand and the board of governors (Headed by Augusta, and with seventy percent being controlled by the voting bloc she , Andi, Amelia and Carolyn have, firmly on her side. He's the headmaster, only as long as the Board consents. (See CoS)
Until next time...