"I was going to pitch one of the demons in first." Probably Meg - she wouldn't harm Castiel, and thus far, wouldn't harm the others because of Castiel. "Not one of the humans."

Because ultimately, Raphael did care about the humans and didn't want them to suffer. And he is beginning to think he hasn't made that clear to his siblings. He didn't really like them, and they were a burden, a heavy one, but he didn't hate them. Didn't want them to suffer.