In some cultures, like that of my mother's, it is extremely rude to press a person to capitulation. It is expected that people should parry in such a way that neither person loses face. In such contexts, talking in circles, softening the argument and changing the line of the argument -- by either party -- can be signs that one person has already conceded. It's not only polite to save the face of the person 'losing' the argument, it is polite to spare the 'winner' from the embarrassment of causing any loss of face. To the extent that if someone ever abruptly concedes an argument in a face-to-face encounter, I assume that they belong to this culture, and I will rewind the argument to see how I offended them -- usually by pressing my argument too hard or too directly.

My father, on the other hand, thought that a touch-down dance must be done on the corpse of every argument, to make sure that it is never resurrected. To not do so would weaken the argument. And I think this is a common American view -- that if you are difficult to throw down and hold down, then your opponent's argument needs to be stronger.

The member of your e-mail list had a third view, which I think is defensible in its contrast to these two extremes.