How do you handle people who become unglued?

Recently, I've found myself in two different -- how shall I say -- "sticky" situations with women who have become completely unglued over something and it makes me wonder if the general population has just raised it's own security alert level from "elevated threat" to "imminent threat". I won't go into too much detail about one that was over a writing assignment, except to say that I overlooked some grammatical errors I should have edited and the person who submitted the content was very embarrassed; but the other was at a restaurant where a woman tried to squeeze her way in between our table and hers, nearly knocking our full glasses over. When my husband touched her back to keep her from doing so, she immediately turned around and proceeded to berate him for touching her, adding that he ruined her whole evening. Then, instead of sitting down at her table, she moved her chair so that it was situated in between both of our tables, so her back was up against our table, causing it to move.

I was horrified. What kind of person comes to a restaurant and behaves so completely irrational? This wasn't a five-star restaurant, but by no means was it a dive. At that moment I thought to myself that I had seen more controlled tantrums from my kids and all the while, I was in a state of sheer disbelief. My husband called the waiter over to ask her move her chair since she would not listen to him, and then she proceeded to go off on the waiter (and us, again). Telling the waiter that my husband "pushed her".

We were almost finished with our dinner and were just waiting on our dessert when this happened. I can't tell you how uncomfortable I felt, and how angry and upset I became -- so much so, that I just wanted to go home. After this woman's "showdown", I couldn't take it anymore, and I called her something that, at the time, I felt justified in doing so. Looking back, I felt like I stooped to her level and I wished that I hadn't, but I was at a loss for words, and my only line of defense was to name call. If my kids knew what had happened, they would have gotten a mixed message. As parents, we tell our children not to let other kids who tease and taunt get the better of them. Here, the taunter went completely under my skin and I let her get to me.

What would you have done, if you were in my situation? Do you also feel as though people, lately, have just become a little more sensitive, maybe irrational? Perhaps just a little more on-edge?