@MrsVISHOUS2012,
The first thing a teacher should learn and keep in mind is that when you start a discussion such as this, although the teacher is in control of what s/he says and has a blueprint in his or her mind for how the discussion will proceed, s/he can NEVER know or be in control of what someone else in the class might come out with or say that could be offensive and hurtful to someone else sitting there.
Sixth graders should not be called upon to defend the nuances or practices of their race or nationality or religion etc. in school.
This is not a discussion I would have started in a sixth grade classroom. Just as if I had intercepted a note that said, 'So and so is a fat, ugly slag,' I'd have not read it aloud and started a discussion about calling people fat and ugly or a slag, calling attention to whoever the note was written about.
Because, know this, everyone in the class knew who wrote the note and who it was about.
A more appropriate discussion to have would be to generally speak about how hurtful it is to call other people names or something like that.
And yeah, I do take this seriously as I know that children and people of all ages are easily hurt and teachers should work to minimize that in a classroom - not put the spotlight on certain kids.