The Solicitor-General has taken over the case against John Banks. As I said earlier, I am not sure we can be confident in their independence; even if we rule out explicit political intervention, most prosecutors will probably see vigorous pursuit of a conviction (which could lead to the Government falling and an election) as a career-limiting move, or they'll simply take an easy plea-bargin rather than going all the way. We need to watch them like hawks to make sure they pursue the case with appropriate vigour, rather than cutting some shady backroom deal to let Banks (and the government) off.
...Except that we can't. Because everything they do will be protected by legal professional privilege, effectively excluding it from the coverage of the OIA. Meaning that we have no way of effectively overseeing them and ensuring they actually do their job in this case. They can't even be held to account through Parliament, because the Attorney-General does not have Ministerial responsibility for law officer functions (and that's a Good Thing).
This isn't a good situation to be in. No transparency and no accountability means there can be no trust. If the charges are dropped, or even if Banks is acquitted, it will look like a political stitch-up. And we all lose from that. After their initial refusal, it would have been better for the government to stay out of it.