While @ZappoNinja was kind enough to answer all the questions that came up, I think I'll elaborate or add what I think as well.
As was stated by Zappo, this is likely due to Venam learning later on about the events that took place. There is already a similar case with this when one saves Amber and Venam isn't required to be around and will gain a point regardless at that specific point and not when you'd tell her on the Valor Cliffside.
A lot of important choices usually reward you in another way. As Zappo stated, the Magma Stone rewards you with Karma if you ch