This is a really interesting take. You're right - it's fairly common behavior (especially in teens). An 11 year old who sobs so readily when caught messing with a candle, though...well, I guess he could still be prone to rule breaking - but he's definitely feeling scared when caught doing anything wrong. If LS did let him go out after being sick all day, then I say he wasn't actually sick (he was, after all, in a car for 4 hours as far as LS's story goes). To let him go to that friend's house without a phone is pretty irresponsible, but the kind of thing a parent might overlook (and if Gannon was determined to go missing, then he left his phone at home deliberately).
The scenario then plays out (and supports LS's statements) as follows:
Gannon is in trouble and experiencing dread due to the carpet incident. Doubtful he was ever sick, but if so, then he is taken on a drive around CS for 4 hours then allowed to go out and play. He is already planning to run away. Maybe she takes him with her for errands because she's worried he'll run away, who knows. He knows someone who will come pick him up and help him out. Maybe parents of a friend? If it's a random adult he met online, then surely by now LE would have detected that on his phone or computer?
However, at this point in time (18-19 days) and with all the publicity, surely the person who picked him up (if a parent of a friend or an adult friend of Gannon's) would have contacted authorities by now (if not, they are of course guilty of major crimes). If that person is already a pedophile or criminal, then I think most of us know how that story will end. But there's been no evidence that Gannon had such an adult friend (and his phone would show it - he would have had to arrange that ride somehow; the chances of that person just being in the neighborhood are next to zero, IMO).
I'm thinking horses not zebras, still.