I found a neat bug when trying to return a city to its original owner.
When you capture a city you sometimes get four options: a) examine the city, b) install a governor and keep, c) blow it up, d) return it to the original owner - a third party. What I found is that sometimes both option c and d blow the city up.
Not a crippling problem, as you can work around it, but still not WAD.
I attached a save game. To reproduce this bug, play the Svartalfar and use any one of the units near Cevedes to capture the city. Attempt to return the city to the Amurites. Accidents happen during the hand over.