That guy wielded a weapon in the estate of an Archduke and tried to hurt someone under the supervision of said Archduke, right ?
Sounds like enough of a reason to punish him a bit before kicking him out, maybe something like breaking that arm and a few lashes...
You can't have some nobodies wielding weapons and hitting people on a noble's property, getting away with it with no consequences.
That would be an insult toward said noble's authority and honor after all...