I'm not very fond of, for lack of a better term, the victim blaming in this thread. This isn't a matter of "you see the T has a gun, stay out of the way" as sometimes it simply isn't possible.
Like elemental said and I reinforced, if it's a matter of a CT trying to shoot a rebel and accidentally shooting an innocent T, that is cross fire. If the CT decides to unload his clip into a group of Ts just to shoot one rebel, that's freekilling and not cross fire. Accidents happen, but there's a line between accidentally hitting someone in cross fire due to wrong place wrong time, and spraying people down.