It is hard to convict operators. I am not sure about this case specifically (it may have been held away from operator bases) but when you court martial them, the jury tends to have a lot of their fellow operators on the case. I saw a case where an operator was charged with descanting a body for collecting ears. He admitted to it. The jury was all operators and they found him not guilty. They didn't see anything wrong with it, despite what the law says.
In the Gallagher case once the medic says he killed the little terrorist, and how, it was over.