Video game tie in here. The term Fragging which is used in Unreal Tournament is actually a term that was coined in the Vietnam war. https://en.wikipedia.org/wiki/Fragging
Some soldiers simply were settling grudges. Some felt that fragging, especially in the wake of particularly idiotic commands, could be an effective way to dissuade other superior officers from similar acts of stupidity or futile loss of life.
Less violent methods of disobedience would include imaginative interpretations of an order.
