Do you answer back when someone is insulting you?

It depends on the situation. I probably would have spoken up if I was you. When you hold things in it only makes matters worse and then you end up regretting it. This will only make you angry at the person and nothing will get better and the next time the person does something you might really say something worse. Sometimes you need to speak up for yourself, especially if you believe that you are right. You can't allow people to get the better of you because then they will alway continue to think it is ok for them to do this to you.

I am quite fiery and so would normally answer back if I was being insulted, but actually a few times I have found that the best way to deal with the situation sometimes is to actually say quiet and not say a word. People will react to a situation more if argument is given back, but it unsettles them if they are insulting someone who says absolutely nothing!

You should answer back in a manner that is not antagonistic. Silence means you're amenable to the issues. Clarifying issues doesn't mean you're disrespectful and in this case, your colleague was the one creating a quarrel. Stressed out your point and don't hesitate to fight back as long as you can justify your reasons and you think you're right.