This can explain a lot! (spoilers for 10x02 )

Oh!!! What if Dean doesn't want to go back with Sam, doesn't want to be cured, cause he believes that would put Sam back at the end of the trials? that if he cures a demon - he dies?
Even if that's not true, Crowley could convince him of that, it wouldn't be worth the risk for Dean! And if it is tre it could explain Crowley taking him away from Sam, Crowley wouldn't want to be shut down.

ETA: the first two trials hit Sam after he "claimed them" - the third - according to the last scene - would hit once the demon was cured.

It would put Sam in the place to make the choice he made 823 again .
Perhaps this time healing could be consensual, with Hanna? Is she the 'sort of angel' who could heal this or the sort who couldn't, like Cas? (never really got why Gadreel could and Cas could not)

Also, BTW, if they just need a little of Castiel's grace, and healing a human leaves some grace in them, and Cas has healed both Winchesters a lot... needle-kink time again ?


On a different, silly note -
Cole: "Listen Sam, ever since I was 13 years old, every night I'd close my eyes, and all I could see is your brother"
Sam thought bubble - Dude, try it when he's sleeping a foot away from you. And you know the raspy way he breathes when he's about to come alone in the shower, and you know the way his eyes and his lips soften when he likes someone, but it's never you - since you were 13? Try your entire life, since before you knew what a crush was you belonged to him, before you knew what to do with your dick you wanted to do it with hi- ew, he's talking about his father.
Sorry :)