I wondered about that too but I figure it's a bit Wild West out there and the authorities don't really care unless someone actually dies. Exception is the Enforcer who will go after anyone who attacks them. (You will respect my authority!!!)
Yes, the Enforcer will target whomever attacked him last, however, that does not make that attacking player an Outlaw, it just makes them the target of a vengeful NPC. Blowing up the Enforcer, now that will earn you a ticket to Outlaw status.