You have to be joking! What you said cannot be serious. A wake vortex encounter is not an unusual event They happen. This type operated in Australia for years quite happily, having wake encounters. The fin came off because of the unusual pilot reaction to it. I would call it bizarre flying practices because I cannot believe the rudder reaction, the scale of the movements, and the rapidity. I'm quite sure even a 747 fin would come off if you did this to it. The fact that regulatory authorities are satisfied that the aeroplane as it stands is fit to continue operating with pilot 're-education' suggests that the cause is known.