Dean was taken aback by Sam's sudden rage while explained some of what happened. How could he have known? He didn't know that Sam came back without his soul. Especially if Dean had come back from hell with his soul intact. Now all Dean felt was anger that Sam would dare blow up at him for something he tried to stop Sam from doing a year and a half ago. Yet when he was about to say something it was Evie that suddenly got between them, to stop Sam. "Evie..." Now Dean felt bad. That she had to get between them to stop Sam when it should have been him. 

Castiel took a step forward as he hesitantly placed a hand on Sam's shoulder. "Sam. Please do not blow up on Dean. I was the one that pulled you from the cage. Sadly when I managed to pull you out, your soul did not make it back to your body as I had hoped." Castiel explained, hoping that this would help clear what Sam seemed so upset about and for Dean to understand what happened. "Fortunately, as I looked for a way to get it back, I may have found the answer." Looking to the brothers this time. "I had hoped...that I could have returned it to Sam before something worse happened. For this, I am sorry for keeping you both in the dark." Apologizing for this secrecy on the brothers. He hadn't meant to bring harm to them to the point to lash out at each other.