Hopefully we'll only have riots where it makes combative sense for there to be riots, and not the chaosfests that were Oblivion's random bloodbaths.
In other words, combat participants who can categorize other combatants based on faction/authority, surrender based on parameters, and otherwise extricate themselves from combat in other ways than dying.
Agreed, with all of the improvements in A.I. that we are supposedly getting NPC's should readily recognize the parameters of a situation and act appropriately. Regarding the original scenario, if a guard starts beating you down in the Imperial City then a lot of people should gawk and start talking amongst themselves, rather than join the fray.
The same cannot be said if the same scenario happened in a Waterfront type are....