I answered that I have had food poisoning, although I am not aware of any specific instance. It's just that I've heard that most cases of severe diarrhea or vomiting that are usually attributed to a virus are usually caused by foodborne pathogens. A friend of ours got really sick after eating at Applebee's, and he is pretty sure that he had food poisoning. Some food poisoning just causes intestinal upset without necessarily causing vomiting, and I'm pretty sure I've had that.
The one time I had swordfish, I got sick right in the middle of eating it. I don't know that the swordfish caused it, especially since I got sick (stomach pains and diarrhea) at the restaurant right after eating it, and was better afterwards, but I figured it must have been something I ate somewhere. I have noticed that I've had problems after eating salmon in restaurants, and sometimes even at home, so I tend to avoid salmon now. I guess that is more of a sensitivity though, rather than food poisoning.