Unless he doesn't know he's being manipped. I'm also wondering if maybe he's doing his own little manip game. Have you noticed that too? I think he knows or suspects something about those shifty Campbells and is possibly trying to learn more about what game they're running.
Sam's pretty smart and he's always been sharp about noticing details.

I don't think Sam is less smart at all. If anything, he's learned a lot and gotten smarter. I do think it's really sad though how he's now so much like John. What he never wanted to be.

We've seen him gradually become less compassionate and more detached over the seasons.
I just hope that his ordeal with Luci hasn't burned out the last and final spark of humanity he has in him.