I'm not familiar with the Helium Wars, nor or any other war that decimated California.

[He's... confused, honestly confused, and being accused of lying about what he is to boot. Briefly, Daneel wonders if this is part of some sort terrible breakdown in his brain, if the abilities Giskard had conferred on him were damaging him severely enough to cause hallucinations. Could a robot ever hallucinate? He's never heard of such a thing.]

I would also like an explanation. I have suffered no injury, either. I am in truth what I say I am. Please don't be alarmed.

[He's rolling up his sleeve as he speaks, as this is the quickest and easiest way to show this. He opens up his wrist, peeling back the artificial skin, and holds his arm out for inspection.]