Nothing wrong with being charged with murder for doing your job. After all, you might be found innocent after 6 months of hell. If so, I’m sure they’ll be anxious to put their lives on the line, once again, for such a grateful country.
You're not really going to give them a free pass on the ground of "chust following oahdahs....?"
I'm not accusing these guys of anything -- it sounds like they did the right thing.
But ... on balance ... it is better for a variety of reasons that inquiries like this can happen. Imagine if actions like this were never investigated.