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]
(..) executed, by my order, for disloyalty and high treason. He deceived me, even though I trusted and rewarded him. And for such deception and treachery, there can only ever be one punishment. Your Grace will now be entrusted completely with the defense of our realm. This is the Iron Hand of Frankia. (..)2016 TvShow: Vikings Title: Portage Season: 4 Episode 8