It seems that game #3509401 is the one in question. If you play as Jamind and load the game at decision 199, you have now Sacrifice in hand as well as Estate-Fortress. If you play Sacrifice and choose to trash the Estate-Sacrifice, the game stops, just as Jamind described. If you reload (CTRL-R in my Firefox), the game says it is waiting for Ingix (that is me).
OTOH, if you load game #3615441 (me vs. Rattington) at the very end, I have just played Sacrifice and the game now wants to know what to trash. If you select the Estate-Fortress, the game correctly returns it to my hand, gives me the +2 Actions/+2 cards as well as the +2VP.
So it seems that something special is going on in game #3509401 that does not happen in game #3615441, though I have no idea what that could be. The previous turns don't have anything special going on.