Sans doesn't react to being picked up or moved every remotely, and almost as soon as he's passed out, his wings and halo have also dimmed to a fraction of their usual radiance and size. Even his bones have gone faint and more ghostly and transparent than a proper angel manifestation should appear - but at least he's apparently stable.

If he was dead, his soul would have broken apart and stopped existing already.

All of his eye sockets are empty for the the time being, which makes it impossible to read his face, even more than usual. As it is, he's left with faded husk of Sans's usual angelic form, laying still on the couch.