This comment:

EY to Kawoomba:

This by itself retains the possibility that something vital was missed, but then it should show up in the surface correspondences of behavior, and in particular, if it eliminates consciousness, I'd expect what was left of the person to notice that.

Appeals to contradict this comment:

EY to Juno_Watt

Since whole brains are not repeatable, verifying behavioral isomorphism with a target would require a small enough target that its internal interactions were repeatable. (Then, having verified the isomorpmism, you tile it across the whole brain.