Sandman.
IMO, a "freedom fighter" uses unconventional warfare (guerilla) methods to attack legitimate government, military, and infrastructure targets in order to acheive his goals. Casualties among the general populace, in this case, can be considered as "collateral damage", a consequence of military action. Blowing up a police station, a government building, or attacking a military patrol are examples of this type of activity.
A terrorist attacks the general populace in order to acheive his goals. Casualties among the general populace are the method and desired effect. Exploding a bomb in a subway, attacking an airport, or taking hostages fit in this category.
I disagree with the premise that "one man's freedom fighter is another man's terrorist". I really think there are objective ways to evaluate methods vs. goals. That's the criterion I would use. Your opinion may differ.