Jack narrowed his eyes. "It's funny," he said, rummaging through his notes, "but I've got at least two examples of your brother being at two places at the same time. Here, for example, where Gilderoi is said to be in the study hall, while another student vouches for him being in House Hydra. What is remarkable is that both times, people claim it was Gilderoi. That means that both of you were pretending to be him, rather than just him."
He sighed, pinching the bridge of his nose, before fixing Galadari with a stare. "Let alone the fact that it would make more sense for him to impersonate you than for him to impersonate you impersonating him. Don't lie to me, Mr. Rubinhart. I know you are rarely as innocent as you pretend to be."