Creating a city on top of a scout

Was messing around yesterday and I had a scout essentially on sentry duty south of my kingdom so I could see monsters incoming.  An opposing sovereign walked directly on top of the scout without initiating combat, then built a city.  The scout was then trapped inside an enemy city unless I chose to declare war on the city's faction.  Probably the scout should have been shunted out of enemy territory, like in Civ 4.