Shinmai Ossan Boukensha, Saikyou Party ni Shinu hodo Kitaerarete Muteki ni Naru. - Ch. 56 - The Dragon's Whim

[Xerand]

I feel like there should be more to all this.
Like, her having a Trauma related to dragons is understandable but she barely even saw a dragon when all this happened.
You would expect her to have had to watch a dragon burn everything down for 4 hours straight or something.

I think it has to do with both seeing that guy's arm becoming dragon and that dragon mark possible reacting to dragon mana. It may not be strictly trauma reaction, but multiple things at once