Angry at a Trigger

Along this journey I am learning more and more about what triggers my emotions, my stresses, my panic attacks. For the most part, I understand why I'm feeling the way I do from my triggers.

But there are some that are really upsetting me. For example, someone says something that's inflammatory, or rude, or negative -whatever. They're POed, they're upset, they're angry. I know it has absolutely nothing to do with me. It's their own inner turmoil that's causing it. But it triggers my anxiety. It makes me feel nervous and angry at the same time. Nervous, because I think "well what's going to happen next?" And Angry because I know "this isn't about you, so why are you letting it affect you and make you feel bad?"

The triggers that are all me I am learning to deal with and overcome. But these "outside" triggers - I just don't know how to prevent them from stressing me. Any ideas?