Crowley told that Christan's been a demon for a very long time....Cas can tell straight away if a person is possessed by a demon right? he did it with Ruby...so, when he was done checking Samuel for his soul and Christan walked in, how come he didn't point out that he was a demon? hope he's not broken or something..we know he has his own issues back in heaven but still..wake-up and smell the demons, man :p
or perhaps he was planning on telling Dean when they were alone so that Christian wouldn't know he was spotted but the whole thing came out before he could..or he was distracted with the heaven civil war thing and having just pulled his hand out of gramps chest..

I must've missed that line somehow!

I think he's really distracted by his own problems these days. Every time he's on screen I just get the feeling that he's only partially there. There's a part of him that's keeping tabs on things in Heaven constantly. We saw how he became distracted in that scene, as though hearing or sensing something happening in Heaven.

^^I agree. Dean/Sam aren't and can't be his top priority at the moment, he has to look at the bigger picture. There is a civil war going on at his home, where people he love are dying, and that is a major distractor for him. He isn't the same Castiel we saw last season to a large extent...he has so much more responsibility he can't really afford to be that "carefree" angel this year.

Yup!!
He is!

I think he's "Gods Bitch" again.. Booo