Alastor only just reaches the minister's office before Severus Snape does the same. The death eater (known, unlike Black it seemed) had apparently alerted the minister before going to pick up Albus and flooing over to the atrium.
Fudge – surprise, surprise – is very eager to go along with Snape's plan and drag the dementors over to Tonks' home. Albus puts up a token protest of this plan but Alastor's seen him convince the minister – as well as much smarter people – of things before and knows he could be trying harder.
"You can't bring dementors onto private property without permission." He interjects before the planning can get out of hand. "And I can vouch for Pettigrew being alive. It'd be a hell've a scandal if he is innocent."
That should stop him in his tracks.
"Well, I, uh, that is to say." He takes his hat off and fiddles with it. How he ever became a successful politician with such an obvious tell is beyond Alastor.
"Perhaps we should go and see what Black has to say, Cornelius." Ah Albus; always the diplomat. Good to see you back on form.
"Well I suppose, Dumbledore, if you truly think it's the best option."
Snape scowls.
"I do. Lead the way Alastor."
He does so – calmly suppressing a smirk in Fudge's direction. He does not miss having to have meetings with the buffoon.
At the other side of the floo they find Tonks and Lupin making awkward, stilted conversation, while the younger Weasley and his friend stand in silence by the fireplace. Potter is still out of the room, which he can see going down poorly with Dumbledore and the minister. Pettigrew's unconscious body is still laid out on the floor.