Should we follow common decency in was?

i dont remember the exact names and dates of this story, but it goes as such, civil war, guy in the south wanted to send a message to a commander in the north, a secret message, well the only messenger available was a female, so he sent the message on a piece of paper with her, she was smart and read and memorized the message along the way, she was stopped at a city by the southern military and was told she was going to have to be searched, !!!!!!!while the military men waited to get a female officer, she messenger ate the message, so that when she was searched she had nothing on her, and was able to continue on and deliver the message, the men followed common decency and therefore lost a valuable piece of intel, the outcome "our country now" shows that this went in our favor but say, the war now, iraq, iran, afghanistan, a female carring a message to a leader, do we follow common decency, or do we search,

im not looking for a better solution, i want to know, do the ends justify the means, do we ignore common decency in places of combat