Right, I ain't used t- what? [Crap, crap, he's been called out, he's been busted...] I - I don't know what you're talkin' about! Who're you callin' a-

[Is there any point in flailing, though? If this guy's not just calling him a robot in general, but knows the details... he settles into a slightly wary look, and quietly, forcefully-]

More importantly, how'd ya know?