once a spy enters an enemy's city, a parchment that comes up says that he has a certain chance of opening the gate. has anyone seen this actually take place? how does it happen? does one have to issue a command to the spy to open the gate or a try (roll) takes place automatically after an army assaults the settlement?

on another note: in MTW (the latest Viking Version), spies used to significantly increase loaylty of your provinces and decrease it in enemy territories; the higher was a spy's valor, the higher the improvement/hit (in the case of an enemy province) to the loyalty. does it happen in RTW? does a spy's valor/experience play a role?