Before reading other responses:
Both Arnold and Nadine have now seen a card in a hidden zone that neither of them were entitled to see. Even though Arnold has legal knowledge of what the top card is, he's still not allowed to look at it. That said, the card was revealed due to a manual dexterity error on Nadine's part, through no fault of Arnold's.
I'd say Nadine has committed L@EC, and Arnold has not committed any infraction. Nadine receives a warning. To fix, we randomize the
unknown portions of the deck. Shuffle the rest of the deck (taking into account any scries on the bottom), and put the known, scried-to-top card back on top of the library.
Since the only revealed card was part of the known portion of the deck, I'd be comfortable deviating ever so slightly and not actually shuffling the rest of the deck, as part of the fix.
After reading other responses:
This seems to be exactly what everyone's saying this week. Just to clarify, the actual text of the IPG on the fix is:
Shuffle the randomized portion of the deck (which may include the cards that were seen, if they were part of the
random portion of the library). This requires first determining whether any portion of the deck is non-random, such
as cards that have been manipulated on the top or bottom of the library, and separating those. Once the deck has
been shuffled, any manipulated cards are returned to their correct locations.
Because the revealed card had been scry'd, it is no longer part of the randomized portion of the deck. We first apply the shuffle to the actual random part of the deck, and
then put the known card in its correct location.
Since everyone's in agreement about being able to skip the shuffle, are there good reasons to
not deviate here? i.e., actually determine all known portions of the library and re-shuffle it?