By definition, communication cannot exist during an argument. In an argument, people want to be heard, not hear the other person. When communication has shut down, there is no reason to continue to talk. It has nothing to do with hiding anything. It has to do with feeling that the other person has no interest in hearing what he or she has to offer.
It may mean that they don't want to talk about it b/c they have yet to find the right way to express something, and to try would be to screw it all up.
i think its more about them being unwilling to put in the effort to convince you
In my own personal experience its guilt and the fact they have something to hide or you found out something that they they would rather you didnt
good quastion.i think they want 2 hide somthin as you said.
its usually because they have **** all to say thats all.
because they have reached the conclusion