Your argument seems to basically be "we can't know what the other helicopter saw, so we have to assume they saw weapons."

No. My argument is that we are lacking a huge amount of context by virtue of having only a single narrow view into this event, through the targeting device of only one of the crewmen in only one of the Apaches, so it's foolish to assume that the statements made over the radio are fabrications based on what we're seeing in this video alone. There are at least six separate viewpoints here; those of Bushmaster 06, Hotel 26 and each of the four crewmen in the Apaches; we only have access to a portion of one of those. Just because something mentioned over the radio is not seen in this video does not mean it did not exist. Of course, it doesn't mean it did exist either, but that should go without saying.

I am convinced, based on what I did see in this video, that some of the men were armed. But I can't say that the crew of both Apaches were entirely in the right in the way they behaved or that they were entirely in the wrong, because I don't think it's possible to make such a definitive judgement without having additional context.

Leaving aside your argument, don't you find the voice track coming from the gunner shocking? The man actually had glee in his voice as he was gunning down people that obviously had no possible chance to defend themselves or harm him. An AK-47 vs. an Apache helicopter is no threat.
As others have stated, at the range from the gunner's PoV, an RPG, even if he had one, cannot hit the helicopter.

If you think that all soldiers shoot their enemies with grim remorse and regret, you're naive about the realities of war. Those pilots & gunners were convinced those guys are all insurgents (which some appear to have been) and they were pumped with adrenaline which tends to produce a slightly euphoric feeling. It has always been like this; do you really think that bomber crews and fighter-bomber pilots in World War II didn't whoop with joy when they scored a direct hit and wiped out a bunch of enemy soldiers? Of course they did. The quiet introspection comes later, when the adrenaline wears off and they're alone with their thoughts back at base.

Your comments about there being no threat to the helicopters are irrelevant, because the perceived threat was obviously to the vehicles of Bushmaster element, less than 100 m from the street corner where the action took place. The Apaches were also flying in a hostile area, where RPGs had brought down Apaches before, so that would have amped the adrenaline up even further.

The fact that there are cold-blooded killers in the cockpit of a helicopter, that take joy in killing innocent civilians should shock each and every one of us.

It's very clear from the video and the investigation that the crew did not think they were killing civilians, so that's a false premise.

Aren't you sick of being an apologist for an unjustified killing in an unjustified war?

That's hardly a fair or honest question. I have made no statements about the Iraq War as a whole and it's your assumption, based on limited evidence, that the killing was unjustified. A reasonable case can and has been made that the killing, at least of the journalists, was excusable when considering the context.

I have not come down on either side of the argument, but I have on principle sought to oppose some of the more knee-jerk reactions that have made unjustified assumptions about the event based only on this video. This is an exceptionally explosive issue so it's very important that the debate which surrounds it is conducted in a careful and logical manner without excessive emotion. Posts like yours, with emotional arguments and inflammatory language, aren't helpful.