Some basic rules in Japan:
1. You are always guilty until you can prove your innocence.
2. The Japanese police are renowned for being strong against the weak and weak against the strong. They will tow away an old crippled lady's car but when the yakuza double park in Roppongi...there is not a policeman to be found.
3. Any accident or incident that happens must be at least partially attributable to you...because if you were not there it would not have happened!
4. As a foreign carrier, in such circumstances, always demand a representative from your government be in attendance when police wish to interview you. In this case the Ambassador saw it as sufficiently serious to attend...well done to him. The Australian Government should now follow up on the issues and anomolies in the Japanese system.
5. Always carry a small recording device.
The Captain is absolutely correct in refusing any Japan trips until this is sorted in writing to his satisfaction.
As someone has alluded to, the basic advice of the Japan pilots union is to have an open ticket out of the country at all times if you are aircrew living in or operating into Japan.
Finally, if the Japanese authorities will not budge on their non-conformist policies, foreign authorities should start harrassing Japanese airlines in subtle ways that will be easily interpreted as a protest against their non-conformist policies relating to
a/c incidents in their jurisdiction.
The Japanese aviation industry, as much as it detests this sytem of interference in aviation issues by the police, is powerless to do anything about it.
Change requires pressure from foreign governments at the highest level.