Who shall Judge the Judges?
The case in question is pretty straight-forward. Judge Wickliffe was asked to rule on a claim for the seabed and foreshore for a tribe with whom she had some connections. The government wanted the case thrown out as the seabed and foreshore bill will remove the Maori Land Court's ability to hear such claims. Since the bill hasn't been passed yet, Wickliffe allowed the case to proceed and then recused herself. The government's position is that she should have recused herself first.
The thing that strikes me is that even if the Government is correct, so what? Her decision to allow the case to proceed was still a correct one as the Judiciary is obliged to follow the law as it currently stands rather than what the Government intends it to be (Fitzgerald vs Muldoon 1976). As a delaying tactic, it's rather extreme in that the Solicitor General could easily think of half a dozen more innocuous excuses to prevent the case from being heard until after the bill was passed.
The only theory that makes sense to me is that the Government is out to punish Judge Wickliffe by getting a judicial review that was critical of her actions. If one was obtained, she might be obliged to resign as has happened in the case of the Inspector General for the SIS over the Zaoui case. While there are valid complaints about the Maori Land Court, this is still a rather extreme way of settling scores.