That'd be pretty bizarre, actually. As far as I can tell, the script always places the lowest-number available government for the AI (I never see lvl 4 governments). Some eleutheroi towns have government buildings, though. Maybe Tamane has a government building as an eleutheroi town at the start of the game which doesn't get destroyed when the Saba take the city because its already their culture and the game thinks its a Saba building?