This is somewhat true but I find a good deal of the time in very heated situations words are simply used to act out raw emotion. Perhaps in place of a physical reaction. There is no subtle message or confession of thoughts better left unsaid, only venting.
In truth speech is a very imperfect tool for personal expression and everything should be taken with a grain of salt, whether it appears to be forthcoming and on the spur of the moment or “through the lens of propriety”