4 Corners or similar would be great if you could lay down the rules for the program, which I doubt very much.
The interviewer would need to ask intelligent questions - always tricky finding journos who can be intelligent about aviation. Then the interviewees need to be credible. That rules out the usual ex international airline show ponies, consultants and assorted PPL experts. You would need them to interview pilots actively engaged in checking and training with knowledge of the aircraft type and its potential hazards ,benefits of simulators etc and the FAA approach to training vs CASA. Somehow you’d need to have all this woven into the story in such a way that the great unwashed public would get the idea that CASA is not blameless in this or many other accidents, that they still have rogue FOIs in their ranks, lack FOI induction training, don’t keep FOI’s competent to occupy control seats to conduct tests, have no proper standardisation across offices etc.
Good luck putting all that together.
Re independent investigation, maybe talk to AUSALPA. They may have a couple of qualified accident investigators on their books.