Voldemort's words couldn't be allowed to affect him. Not until this was over would Alastor let himself think about lost men. Couldn't afford the distraction.
He huffed under his breath at the snakes. Unlike the inferius, these he could slash with impunity and he did. But, the distraction they proved to be was all it took. With his eye spinning in his head trying to keep track of things around them, Alastor was just seconds too late to stop the curse from hitting Vaisey.
Growling with his own rage, he turned to meet Voldemort one-on-one, he also had to dodge portions of the collapsing ceiling, which gave his quarry just enough time to make another fortuitous escape. Through the smudged and dusty shop window, Alastor could see back-up finally arriving on the scene. But, rather than signal to them, he picked his way across the floor, avoiding debris as necessary.
When he reached Vaisey's still form, he knew he wouldn't need to touch him to confirm what he'd known as soon as the man went down. They'd lost another one on Alastor's watch and he was beginning to be personally pissed off at the bastard he had to thank for the lives he counted on his own head. Kneeling beside Vaisey, he lifted the man carefully by the shoulders before apparating away.
Let the politicians deal with the fallout. Alastor's priority was taking care of his own.