I'm not sure if this is a bug or not, but in the weapon depot battle (the one pictured two posts above), at one point the enemy soldiers starting attacking bridge tiles I had made that had no use to me instead of pursuing me.
I had cleared out all the enemies on the map except for the two archers on the far left elevated region and the enemies that show up with the leader. I had moved my units into the base in the middle of the map, and was setting up to really hit them hard once they came inside while also looting the barrels. Two enemy swordsmen were ahead of the rest of their party, and they just started attacking the bridge tiles. These tiles just extended 1 square into the water; they did not even reach the other side. The swordsmen could have come around the base to attack me instead, but it was like they got distracted by the bridge tiles and decided to ignore pursuing me. (I didn't know of these forums at the time, so it didn't occur to me to take a screenshot.)
Again, not sure if it's technically a bug, but the AI seemed screwy. I guess it could have made sense if they were waiting for the rest of their party to catch up them and decided to just do that instead of standing there, but it didn't seem that way.