I had a case where the opponent as an Elf did a DD, he was dismissed, I dug him up and it wouldn't let me do a DD; the opponent was red and I was blue
There is logic in this, absolutely clear: during the blue player's turn, it is still the same game day that just passed for the red player, and the description of the "DD" spell explicitly says "so-and-so times per day," not per 1 turn.
But the situation with Fiona is a clear bug, and it's unclear whether it's from the HD mod, HotA, or SoD in general.