I can understand that. The ninja's arts are aggressive precisely to do just that. End a fight swiftly, because you or anyone else can come to harm. It isn't nice or pretty and many people would call it dishonorable, but in my view, the real dishonorable thing is to obey some sort of code or stricture that gives an enemy you know needs to be taken down a chance to win or get away and cause more pain and suffering.