Doesn't sound like you understand trauma very well. Even something as minor as being injured in a mosh pit can be traumatic, especially depending on how old she was when it happened.
Just because she was fine at other shows doesn't mean this one couldn't be triggering for her when she got separated from OP. Look, she has SOME responsibility for blowing up and acting irrationally, because the way she handled the situation was poor to say the least. However, OP also has some responsibility given he knew large, rowdy crowds were a problem for her and he didn't make an effort to find her until after the show. This is a pretty common type of miscommunication between couples, where each person judges the situation by their own comfort level/perception, without considering that of the other person.
Again, I explicitly said in an earlier posts that an event like that could cause trauma. I'm just saying no one here is in a position to assert she was traumatised when as far as we know she didn't even use that language.