Interesting. In my Marine Corps, you are expected to think. You must at least have the awareness and reasoning capacity to distinguish a lawful order from an unlawful order, and to act accordingly. We are not robots.
Consider Puller's comment, "generals are a dime a dozen, but a good shotgun is hard to find." The thinking should focus on your duty and the commander's intent of objectives. Marine leadership teaches Marines what is important to focus on, gives them knowledge and promotes the developement of wisdom within them to enable them to produce results that fulfill the commander's intent.
This soldier was a private under the guidance of older, senior noncoms and officers. She was following their lead. Unless she is more knowledgeable and wise than they are, it is unlikelikely she would ever know in the short term what she was actually doing. Now she will be told that what she's done was wrong and why it was.
They were not torturing and killing prisoners. It is doubtful she could have told the rest of the bunch that they were doing it all wrong and they should do what she suggests.