Hey, that’s something, getting an apology out of an angel? Castiel even looked kind of down about the whole thing, which, okay, was a bit weird, and definitely something he wasn’t expecting. Did angels even feel guilty? Was that ...normal, for angels? He didn’t really know; his visions-or-whatever weren’t exactly reliable for that sort of thing.
”Hey, no worries. It’s fine.” It was slightly less than fine, but whatever. “Just, ah, you might... wanna be less, um... sudden? With your arriving?” It felt wrong to be telling an angel to do - or not-do, in this case - something, but, hey, Dean did it all the time, and he hadn’t been smote yet, so Chuck was pretty sure Castiel wasn’t going to kill him for the suggestion. Whether he’d heed it or not was another matter entirely, though.
“So, uh, what’s up?” Wow, could he be more awkward if he was trying?