Its almost confirmed!!!A moderater at the .com tested it out and got the same result..looking for others to test it now...my latest post :

Oh boy!!!Here's more findings...The custom battle i posted isnt reliable either...LOL

Updated crash criteria:
- 2 AI armies
-Siege battles
-Settlement/castles with wooden defences
-AI army uses firing siege equipment
-AI army attacks towers that are under control either by you or the other AI!!!
-The AI army firing the siege weapon havent moved their infantry yet.

6 criterias now. In testsiegebug.cbx i gave scots like 4 or 5 units...at times after a single wall was breached they sometimes rushed their units in. The crash didnt happen when they attack the towers after they rushed their infantry in.

New custom battle :
http://files.filefront.com//;7548015;/

In this siege move the english army closest to the spanish line during deployment phase..this is to avoid enemy units from moving to the english side...unrestrict camera and just observe the spanish army..wait till a tower that is in control by the scots get attacked...the six criterias have to be fulfilled to crash...there is some random element in the AI decision so if they move in after a wall breach its not gonna happen..You have to wait for the AI to do things like i said..And wait a while more as at times it doesnt crash immediately the towers are attacked..this is especially if the tower was not in control when it was first attacked..but it will crash...just check it out.