Don, on the other hand, looks like he's been sleeping quite well.

"I was with a friend. You knew I was with a friend. Why are the two of you acting like this?"

He asks the question, and finds that he's suddenly unapologetic about his disappearance. He didn't do anything wrong, and on some level he resents that his brothers were so unreasonably worried about him. As though they didn't trust him to look out for himself. Well, maybe they were right. But he's already suffered for his errors in judgment, and he's not going to listen to lectures on top of it. Not if he can do anything to avoid it.