On one excercise, I was leading a section sized patrol back in. Our last task was to sweep the company fall back position - part of which was an open area about 50x50m with patches of grass to knee high, a little scrub and a few fallen logs. A kneeling person would be completely visible. We were stopped by a "friendly" master warrant officer as we approached the area and were specifically and repeatedly ordered not to sweep the area. Under protest we went back to our lines. Of course the obvious happened - we fell back right into the enemy platoon with support weapons hiding in the open ground we were ordered not to sweep. 8 pairs of eyeballs saw nothing.
I was later able to return the favour when I was bartending at the senior NCO's mess.
I'm very happy I never had to play for keeps and very grateful to all those who have done so or who are doing so right now.