I don't know, he is very clearly praying to a 'mistress', so your intelligence will have to be 3 to not connect the dots. Abdirak was just an example, that came to mind, because you have not one, but two books about Loviatar laying around in his corner of the camp. Maybe they overlooked it.
Me neither ...
But as far as i know, litteraly everyone can worship any god ... priest, or not priest. O_o
Im just saying that there is other ways to look at this scene.

Maybe your character was so interested in those books, so s/he didnt notice his prayers. :P