He's leaving deliberate holes, yes, but he's giving him just enough clues for Chuck to be able to piece it all together. It might take him a second or two, but really... in the end, it's kind of basic storytelling? And if Chuck is nothing else, he is a storyteller.

He got a degree for it and everything.

He takes this time to take another bite of his sandwich as he thinks things through. The sandwich is really good, though. And he's not just saying that because he lives in a house full of angels that have no idea how to cook whatsoever.

"How did you get out of Purgatory? I mean, that's just like being trapped in Hell, right?" It occurs to him only after he says those words that Dean's memories of Hell probably aren't something he wants to think about. "Uh, sorry."