Random thoughts...MOO
--It isn't logical that LS/TS would give him to someone with the intent to produce him at some later date as 'found'. He's 11 and can tell people what happened (barring some physical reason that he couldn't). Maybe she thought she'd be long gone when she gave the 'password' to the person holding him to drop him off somewhere?
--It is possible that we didn't see GS get out of the truck because he was still in the backseat, possibly sleeping/drugged. And then if she did pull him out of the truck later, neighbor video would show this, too, or at least her revisiting the vehicle. Did she not know about neighbors having security video? There is likely more than one set of images.
--If she was capable of driving him somewhere and dumping him, leaving him to the elements, then I have no words.