I ran into found this bug while fighting the Yithril city containing the Yithril spouse. She escaped onto the road leading to my next conquest, so I killed her--but the body didn't disappear. I could not move along the road she was on to take the next city, without attacking the body, and the move cost for leaving the road would prevent me from taking the second city this turn. So in frustration, I attacked the body, autoresolved, and "killed" her again--and got all the loot and bonus XP for killing the spouse. This kept working, so I went up 3 levels in 3 turns by attacking the undead spouse.
This did not happen with the other spouses, but the bug/exploit stayed even after reload. Every turn the Yithril spouse was resurrected and could move, attack, etc. normally, and every turn I would kill her 8 times for tons of XP. The madness did not end until I autoresolved a battle while she was standing on the same space as a caravan, and her body disappeared finally. Of course, by then it was too late. My army of level 10 sand golems and summoned bears tore through the rest of their pathetic empire to win the game. Still wonder what the deal was, though. This was the last empire standing, but there were still Kingdoms and such, so it wasn't the last spouse character on the map. Has anyone else run into this?