While the strength of the Court of Appeal's judgment may discourage an appeal to the Supreme Court, if the case did go forward and the court granted leave to appeal, it could be months before a hearing took place.
Labour leader David Shearer yesterday said Sir Douglas should not wait and should hand back his knighthood. "That would be the honourable thing to do.
"He's done some wonderful things in his life but I think in this episode he really does need to consider whether he has that knighthood."
Mr Shearer said Sir Douglas would be remembered for the good things he did even without his title but "there are thousands of New Zealanders who lost their futures and their life savings because of the actions and decisions he took".
Meanwhile, Mr Key indicated the decision would be a difficult one, should he have to make it, as he could see both sides of the argument.
"It would be a big call to take a knighthood off someone. The only example we've got in New Zealand's history is the former Cook Islands Prime Minister Henry and he was found to be defrauding the state.
"Even in the UK where there's been a tradition of knighthoods for a very long time, there's been very few that have been taken off people. On the other side of the coin, I accept the seriousness of this matter."
The judges who heard Sir Douglas' appeal "make it quite clear that they don't believe he intentionally acted dishonourably or with intent".