Nonetheless, the ministerial resignations of both Banks and Dunne does reinforce the perception that the stability is as wobbly as blancmange.
Key will be relying on those assurances more than he is letting on. He has pointed out he can still muster a majority with the Maori Party. But the Maori Party votes against far more government bills than it supports, and that leaves vast tracts of National's policy platform at risk of being put on ice. It would still be able to govern, but only in first gear.
Politically, it is atrocious timing for Key, who had hoped to spend this time trying to be a pernicious gooseberry on new Labour leader David Cunliffe's honeymoon.
Instead, this imbroglio will help the budding momentum Labour has built up. It won't take much for Cunliffe to play on that perception of instability, and suggest National is now relying on a ragtag bunch of minor players with question marks over their honesty.
The timing also adds to National's longer-term headache - future coalition mates. If Banks does appeal against the pre-trial decision and that appeal fails, it will simply have served to drag proceedings out and could mean he still has a trial hanging over his head heading into next year's election. It would be untenable for Act to stand him as a candidate. Even if Banks is cleared, it will be hard for Key to justify asking Epsom to continue to vote for him in 2014.
As for Key, he will be hoping another adage doesn't come true - that bad news comes in threes.