Or maybe HMHB the Senators could refer the matter to the ACLEI for non-compliance with the AGIS....
The tasked investigator will conduct an investigation to provide the Manager EPP with a report and recommendations in accordance with the procedures set out in the Investigators Manual which incorporates the Australian Government Investigations Standards.
Good catch "K" there is some good stuff in that enforcement manual, if you can care to read it
Ah yes the AGIS yet another FF obligation that they appear to merely pay lipservice to:
The Australian Government Investigations Standards (AGIS) establish the minimum standards for Australian Government agencies (agencies) conducting investigations. Where the AGIS are in conflict with law, the legislative requirement will prevail. AGIS applies to all stages of an investigation.
An investigation is a process of seeking information relevant to an alleged, apparent or potential breach of the law, involving possible judicial proceedings. The primary purpose of an investigation is to gather admissible evidence for any subsequent action, whether under criminal, civil penalty, civil, disciplinary or administrative sanctions. Investigations can also result in prevention and/or disruption action.
The term investigation can also include intelligence processes which directly support the gathering of admissible evidence. (NB: 'admissible evidence' JQ would get a laugh out of that one)
http://www.ag.gov.au/RightsAndProtec...GIS%202011.pdf
And the “Investigators Manual” which would appear to be yet another fabled, much referred to work of fiction.
Much like the SPM and the long awaited regs the IM will soon become reality, that is once flying fiend and his crew pull their finger out….err that could be at least another decade 
given Oleo’s comment on the progress of the SPM.
Although flying fiend and his crew have dutifully complied with some of the terms of the AGIS throughout the 221 page ‘Enforcement Manual’, I’m afraid some of that may need to be duplicated in the yet to be promulgated IM. So here’s a helping hand 'flying fiend' for some essential content as per the AGIS 2011
:
1.1 Investigation policy
The agency is to have clear written policy in regard to its investigative function. The policy should include:
• a statement regarding the agency’s objectives in carrying out its investigation functions and use of sanctions
• a clear definition of activities applicable to the agency to which the AGIS apply. This should include a description of compliance activities that are not generally considered investigations by the agency
• a statement regarding the agency’s responsibility to manage matters that are considered minor or routine, and
• a statement regarding the agency’s responsibility to refer criminal matters to the Australian Federal Police (AFP). This should include consideration of joint agency investigation teams, where appropriate.
If they haven't done so already perhaps the good Senators should be asking for the paper trail that shows compliance with the AGIS.
While they are at it maybe they could request that the Part IIIA investigator responsible for overseeing the FF accident investigation present to the committee to give evidence