In Sanhedrin 92b it is Mashma that (at least in Olam Hazeh) someoen who is revived from the dead is Mechuyav in Mitzvos. Otherwise, their Tefillin wouldn’t be Kosher, and they wouldn’t be able to marry.
Now I see that the Ritva you mentioned actually uses this to prove that they are Mechuyav when they get up. Perhaps the Diyuk you are talking about is the Shita that the Ritva is quoting. Although I have to say, it is hard to be Medayek from the on ewho is asking on them. For all you know their answer will be to be Mechalek between Olam Hazeh and the future Techiyas Hameisim. One is an Olam Chadash while the other is a reversal of Misa, maybe.