Even more sinister conducting this type of action in a built up area with this type of equipment in my opinion, ground forces would probably not have made this mistake but then they would be under threat themselves.
Just a heads up, this is standard for AH-64 pilots. Typically, the AH-64 will stay some distance away out of general view, maintaining a hover. Then, when they fire, they pop up (if behind a hill or some such object) and fire their weapons from a safe distance, minimizing the risk of injury or death to service members. Yes, it is incredibly brutal, but it also highly efficient, and NOTHING is going to survive after taking a 30mm round. Had they used a ground force to engage the same target, they would have run the risk of alerting the people ahead of time or suffered casualties.
As for the video, I can't watch it for some reason, but I highly doubt the pilots comments are offensive, being a prior service member myself. I've heard just about everything that could be considered "offensive" by an outsider. If you think military members are always supposed to have a deep respect for life (ESPECIALLY pilots) than consider this a sobering opinion on the state of mind of the average soldier.
I'm not saying I agree with it, but that's just the way service members are. However, the intelligence officers in command of that should have some serious shit about to head their way for getting two Reuters people killed.
EDIT: OK, found video on Liveleak, here's post-viewing opinion:
Again, I fail to see anything truly offensive that was said. Soldiers talk like that, and to link it to video games is stupid. I've heard WAY worse.
Pilots are not to blame for engaging the van. They assumed that it was insurgents helping out, which according to their intel was correct in their mind. They did not fire until cleared to engage by command.
As for the insurgents, weapons are clearly visible, so intel was accurate in regards to insurgents being present. A soviet RPG is pretty unmistakable, and you can see it clear as day, and one was leaning around a corner. If people are hanging around them, the pilots are going to assume they are part of it. Is it a tragedy? Absolutely. But unfortunately, innocent casualties are always going to happen in a war.
I do think the military should have immediately released this and not sat on it because they just screwed themselves in the long run.
Also, regarding the van: US Military ROE can allow for attacks on individuals assisting insurgents. The pilots had no idea if the guy who was crawling was an insurgent or not, if he had a weapon, if there were more insurgents/weapons in the van, etc. Based on their intel and what they had observed, they acted exactly the way they were supposed to.