I don't believe this is bias
@Merilirem. Just circumstantial evidence. We don't have the full picture right now so the gaps are filled in with what we do know. And we know that the son is trash, and all the nobles introduced thus far other than 1 is also trash. Given this, it's a logical assumption.
Is old, but I kinda wanna write up something about it.
There is nothing such as circumstantial evidence. The purpose of an evidence is to prove someone is guilty or not; being circumstantial would eliminate the purpose of an evidence in the first place.
On another hand, being asshole is not a crime. You cannot convict someone for trashtalking you down, for teabagging you in an FPS match, for roping their turn in a turn-based game; however, causing injury to another person unjustly is a reason for crime and can be brought to court.
I like this chapter. It gives the trashy noble nobody a ground for his character and showed some worldbuilding stuff at the same time. He got a reason to do what he does, which makes his character more weighty than the cardboard cutout "generic bad guy that will get beat no. 3". It also gives weight to Desir's plan; he is really going to fight against the system itself as a consequence of "trying to save his beloved ones".