I don't think the Romanian Revolution counts as a civil war. Over the space of a week or so, it was: protests/riots, violent crackdown leading to military defection/coup.

Look at Syria for how a similar pattern of events did lead to civil war. Ceaușescu just didn't represent a section of the country with an interest in fighting for his regime. The risk of instability when an authoritarian passes is if they have been holding together a country with significant ethnic/sectarian/political divisions like Yugoslavia.