In every case I've heard of where someone was pressed for misrepresentation, it was for actively misleading the other party.

Verbally agreeing to the NDA then not signing might count. Signing a fake name would obviously count. Editing a digital contract before signing might count, and not highlighting the edits in a "track changes" negotiation would probably count. If you returned the papers and said "these are all set" or something, I guess you might be at risk.

But just... not signing a thing? If someone puts it in front of you without negotiating or asking for consent, then accepts it back unsigned? I've never heard of a lawsuit arguing anything even close to "I handed him a paper, so he should have spoken up to tell me he wasn't signing it", and I can't imagine it'd go anywhere.

(On which note, every NDA I've seen has been explicitly brought up to ensure that I was ok with it. But I guess that's not universal?)