Corvo's prepared to argue that he didn't give up, that he simply did what he needed to, but he doesn't. He doesn't because the rest of that statement leaves him utterly unprepared to defend himself. It's clear that he hasn't actually thought about it in those terms, in that way, and hearing it feels like the air gets sucked out of the room.

Corvo sits back, staring at a point past Richter for a very long moment.

He's silent, though all defenses have gone out of him.