Ok, I'm not going to try and justify any actions here, and none of us really know enough facts to say what happened, but perhaps a little devil's advocate:
On the first mission, they legitimatly engaged a hostile force. An RPG will take out an apache, so that's fair enough. A vehicle pulls up and retrieves the bodies. Bare in mind, these bodies are still armed. The apache engages the van. Shortly afterwards, the apache spots movement and guides ground forces to two children who are taken to hospital. I would imagine that anyone who had fired on children would feel awfull, and shifting the blame to the people that took them into harms way would be a natural reaction.
In the second case, you are told to enter a building believed to be a Taliban location. You go in, engage the policeman and his brother (no one has denied or refuted they were Taliban and armed). You're twitchy and just engaged the enemy when a noise causes you to turn and engage another target, which turns out to be a pregnant woman. You panic, realising you have shot an unarmed civilian, so you try to cover it up.
Now, I'm not saying that's how it went down. I'm not saying any of it was right, but whether you believe we should be involved in any of these conflicts, mistakes will be made. As in society, the US Army has sadists, people who make mistakes, inept soldiers and every other facet of human behaviour. I'm also not saying that these things should be thouroughly investigated, and where fault is found it should be dealt with accordingly.
Just makes you think a bit more about the human condition I think.