In that moment Dean was sure he knew why she didn't want him near, what the 'this' was she was talking about earlier, and where that awful coldness came from. It didn't matter what the 'it' was she gutted, because if it was someone familiar she would have said 'I gutted Sylar," or something of that nature. It was a bad guy who she had gutted, Dean was certain of it, both because he thought she would have told him otherwise, and because he didn't think she would gut anyone or anything for no reason.
That left just one question:why?
Why had she gutted the thing instead of stabbing it through the heart or cutting off its head or something fast?
Shaking his head, Dean decided it didn't matter. She was in no condition to discuss it, and he was going to make her get the rest she needed until she was better again. He didn't flinch when she looked at him unblinkingly, though the knowlege of what she had done was clear in his eyes. Instead he leaned in to kiss her. He said the one thing he was sure of.
"It's alright, Claire. You're home now. It's over."