And that makes a difference..... how, exactly? In both cases the individual is defined as a refugee i.e. it simply doesn't matter if the oppressor expelled them or if they have fled out of fear of that oppressor. Either way that person is a refugee, and therefore has a right to return to his home.
Amnesty: Israel's 'Black Friday' Gaza strike a war crime (Haaretz)
from the article: A softer touch on the Nakba