Wasn't the Tiger 'show clause' due to failures in dealing with the incident(s) (i.e. a below average safety system) not the actual incident.
If you read the wording from CASA above, they say that Jetstar reported the incident as they would expect and are only investigating if the Jetstar internal investigation followed the approved process.
I read into those statements that CASA is not concerned with the actual incident but about the safety system in place and how the airline 'rectifies' these issues.