I'm playing as a Priest of Wael and Grimda doesn't seem to recognize this at all.  Getting the scroll and then listening to Wael and hiding it results in Grimda ignoring me.  So...I'm playing as a priest...of Wael...with Clever and Deceptive as preferred Dispositions, yet Grimda says something like [Deceptive 2] 'I should've known better than to trust you.  You're every bit as wily as those thieves.'

 

Uhhh...wha?  Talk about odd dialog.

This, and the fact that apparently there is no actual way to recieve "Wael's Boon" sort of put a damper on my priestess of Wael playthrough (though the latter is more an issue of the wiki being incorrect--so also not a bug). Being a follower of Wael, however, is its own reward...