Was Alice conscious in case 1? In case 2? Since the sequence of events in both cases were in fact the same exact sequence of events - not merely identical, but referring to the exact same physically realized sequence of events - up to our quantum coinflip, it's nonsense to say that one was conscious and the other was not.

Well, Scott :

that you and I are conscious seems like a pretty clear paradigm-case. On the other hand, that you and I would still be conscious even if there were aliens who could perfectly copy, predict, reverse, and cohere us (very likely by first uploading us into a digital substrate), seems far from a paradigm-case. If anything, it seems to me like a paradigmatic non-paradigm-case.

I disagree with his caveat for consciousness, since I would like to think of myself as conscious even if I am a simulation someone can run backwards, but I am not 100% sure, because reversibility changes the game considerably. Scott alludes to it in the Schrodinger's cat experiment, by noting that death becomes reversible (in the QM-sense, not the cryonic sense), and thus largely loses its meaning:

I claim that there’s no animal cruelty at all in the Schrödinger’s cat experiment. And here’s why: in order to prove that the cat was ever in a coherent superposition of |Alive〉 and |Dead〉, you need to be able to measure it in a basis like {|Alive〉+|Dead〉,|Alive〉-|Dead〉}. But if you can do that, you must have such precise control over all the cat’s degrees of freedom that you can also rotate unitarily between the |Alive〉 and |Dead〉 states. (To see this, let U be the unitary that you applied to the |Alive〉 branch, and V the unitary that you applied to the |Dead〉 branch, to bring them into coherence with each other; then consider applying U-1V.) But if you can do that, then in what sense should we say that the cat in the |Dead〉 state was ever “dead” at all? Normally, when we speak of “killing,” we mean doing something irreversible—not rotating to some point in a Hilbert space that we could just as easily rotate away from.

Since this changes at least one fundamental concept, I am reluctant to state that it cannot apply to another.