I'm sure Kelly is a very nice person in real life, but the thing that really bothered me was when she would call him a "piece of red-neck white trash", or words to that effect. My opinion of her took a nose dive after that big time.
I agree with you really. I think it was her worst moment (even worse than the POW comment, for various reasons), and I was even kind of hoping they would be eliminated after that episode, because I didn't want to see them fighting.
However, Ron obviously forgave her. It was a comment made during a bad day (Ron wasn't being very nice to her that day either.) I guess since Ron gave her a second chance, I did too, and I enjoyed her a lot more when I watched the insider videos, than when I watched the show.