When Person A says, in reference to Person B, "he always has to get the last word in!" obviously Person A thinks this is not an endearing trait, but we also sense his frustration that he always fails to get the last word in, which was his ambition in the first place. Kinda ironic, no?
So in your case, @
Papa Tom, the problem seems to be that you don't actually want to get the last word in; but you have a talent for summing up the situation such that readers think "yup" to themselves and move on. It's really not a problem at all. But if you think it is, well, that's your problem....