In my current game, The Empire of Umber had successfully cleared the city of Dioscrynes (sp?) in the Shroud wildlands and was using it. Good for the AI! However, as I was at war with Umber and taking his cities, I noticed several monster lairs still intact (cobwebbed homes, Shrill Lord Lair, etc) that still held a magic item each. The monsters were all defeated and they were all just sitting there waiting to give up the goodies.
Can the AI take these items and equip their heroes now? Or is this coming in the new patch?