In the end, the trouble that Fen caused didn't bring an axe to his neck. No matter how the young man looked at it, just being questioned by the lazy guards in one of their offices was definitely way too little of punishment for randomly attacking a person in the street with clear intent to kill.
And it didn't really matter what kind of circumstances caused this situation. Growing up in the forest, Fen knew that if he were to randomly attack some beast, then no matter how much he would like to back down, later on, he would never be given the chance to do so.
