It was a misunderstanding on her part, not a deliberate 'deception' on his (part). [=he didn't try to deceive her or lie to her]
The article describes the government's use of 'deception' [='deceit'] to gain public support for the program.
She 'practiced deception' on her unsuspecting clients. [=she deceived them]
(..) Apostol, why are you struggling? Why don't you tell me what bothers you? I understand. You thought that i was a man with a special spiritual structure. And afterwards... The deception... I am a human being, Apostol. That's all. What are you up to? What are you looking for? To destroy the projector. (..)1965 Forest of the Hanged