Section 49 of the TSI Act has nothing to do with the physical thing that is the CVR box and its electronic component innards.
Section 49 of the TSI Act is about the sounds that are recorded and stored in the CVR box.
The prohibition in section 53 of the TSI Act is about the unauthorised copying of the recording and unauthorised disclosure of the information contained in the recording to someone else.
If I remove the CVR box and listen to its contents, and I don’t tell anyone what I heard, what offence do I commit? If I remove the CVR box and listen to its contents, and make a public statement to the effect that it contains information that in my opinion is directly relevant to the investigation of the ditching of NGA, what offence to I commit? It’s merely a statement of the bleeding obvious.
Unless the Chief Commissioner has given a direction under s 43 to the effect that the CVR not be removed from NGA, where is the impediment to someone recovering the CVR to use it precisely for its one and only intended purpose? (A direction to that effect under s 43 would probably be unlawful, because it would be completely contrary to and a complete perversion of the policy of the legislation.)
Any objection by ATSB to the recovery of the CVR by a third party and delivery of a copy of the contents to ATSB would simply expose ATSB’s motivation as craven self-interest.