John is obviously pissed at Sam for not killing him and therefore Yellow Eyes, but I think its really interesting how he seems more surprised than anything. Like if it was Dean he would be straight pissed, But here, he looks more surprised that Sam prioritizes family over revenge, when he left his family for college. He might be surprised that Sam doesn't resent him as much as he assumes, which is why he's not that mad. John takes it all out on Dean because he knows that he will always be loyal (presumably), and doesn't on Sam because he already lost him once. Just a thought, but this was interesting on a rewatch.











