When used in an argument, a person takes various scraps of talking points and tosses them together into a bowl, then tries to pass the word salad as a cogent argument.
In discussing the Boston Bombings and the Republican Congressmen who should understand the Constitution as pertains to the rights of American citizens, a commenter referred to the president as "Obummer" and said that the article about Republican Congressmen should have been entitled "Obama doesn't understand the Constitution" because the borders are not secure and Mexican drug cartels get guns. The comment has nothing to do with the article and can be dismissed as argumentum ad saladbar.
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.