Specifically:
1) The company had been under fire all morning and the Apaches were called in by a soldier on the ground under attack at the location where the journalists were;
2) Among the group of men the two Reuters journalists were with, there were armed men an AK-47 and two RPG launchers, one loaded (and if you can tell that what the journalists are carrying are cameras and not weapons from the grainy video, in real time, you've got sharper eyes than me);
3) A portion of the tape is missing in which the helicopters engage armed insurgents that are seen running into a building; this portion precedes a section visible on the tape that shows the Apaches firing at the building with a missile.
So no, the soldiers in the helicopter should not be tried. If soldiers are in a theater of war, are called in because other soldiers are under attack, and see people with weapons, they should shoot, and that's what happened here. This was not one of those cases like you saw in Vietnam when soldiers just started shooting up civilians with no threat in sight.