Hermione knew that Draco wasn't an ally, but a small part of her continued to hold out hope that she might've been wrong about him. Antonin seemed assured that at least for a little while he'd been on their side. Rodolphus believed the same. Who was correct? She decided that much like Kingsley Shacklebolt, Draco was only doing what he thought was best for himself. He fought for only one man.