I'm not disagreeing with you, panic/ptsd triggers are a real and terrible thing, but in this context I think the use of "triggered" is referencing the current-internet-pop-culture-meme usage of the word.

Some examples:

   "Have a nice day ma'am"
   "Did you just assume my gender?!?"

   (paraphrased from Tropic Thunder)
   "What is it with you people?"
   "What do you mean 'YOU people'?"

   http://i.imgur.com/l2tY2wf.jpg
   http://i.imgur.com/4Kw9O5g.png
   http://i.imgur.com/199QTf6.jpg