Bucky himself never had any fancy night vision technology to begin with. All he sees down there in the hole is a vaguely human shape. But he recalls the noises he was hearing, and he's cautious.

Crouching down, he tries to make out more. No luck. So instead of offering a clear and definitive reply, he simply says, "That depends. You gonna try to kill me if I get you out of there? I know it's tempting, but that wouldn't end well."