Many seem to miss that distinction, though JMM grasps it quite well.

The civilian concept of self defense is not directly translatable to combat. Nor can the actions of Police Officers, charged with protecting the public be equated to armed forces in combat, charged with killing enemies (all other aspects of warfare are essentially political). Two very different mindsets are required and developed. Some will say Armies should not be so trained, that could be but it's irrelevant, at this time they are...

Fuchs makes a a very valid point:
...Also keep in mind that these men were highly trained and not mere enlisted personnel or even conscripts. You should be able to have high expectations of their judgmental abilities or else you shouldn't entrust them a multi-million dollar machine of war for a combat mission over a densely populated city.
What he elides is that they were highly trained combat aviators in a combat situation, doing what was almost guaranteed they would do. The real issue for many is perhaps whether they should have been in that situation, as Fuchs says in the last phrase. Whether they should have been or not, they were there and to expect other than a combat mentality effort is at best naive.

Many are commenting on the video, while several have commented that this is an extract and that some context may be missing, few seem to be recalling that this incident was thoroughly investigated and reported at the time and even fewer seem to be considering what the US Troops on the ground were telling the Apache crews. Those folks were not as highly trained and saw different things -- as much as one sees while the adrenalin flows -- different than the Aviators saw at the time and quite different than viewers of the video see today...