But Key will be betting the damage is confined to Collins' own future options rather than National as a whole. It has already gone on for two months without any discernible impact on National's polling. If any damage was caused by last weekend it will be shortlived - after all, Collins lashed out at a member of the media and that is not exactly an institution there is much public sympathy for.
What Labour is hoping is that the public have picked up on the general vibe. The central figure of Collins has been running through the gamut of emotions on television - anger, tearful humiliation, vengeance, regret, defiance, fragility. Labour deployed its team of forensic experts to comb through the documents released under Official Information Act requests to probe for even the smallest inconsistencies to keep the story rolling.
Yesterday, Labour pulled back and reserved its questions for the Prime Minister instead, wary that pushing too hard on someone under stress would make them look like bullies. When Collins returns next week for the Budget, Labour has little choice but to focus on the Budget rather than her so it cannot be accused of being distracted from the back pocket issues it claims as its mantra.
As for Labour, Grant Robertson wanted Cunliffe's job last September. Last week, things were so fragile he might have been in with a chance. List MPs were doing the numbers as internal polling showed them diving into the low to mid-20s and Cunliffe with stratospherically high negative ratings.
One poll was reported to have Labour only five or six points ahead of the Greens. Emerging from the election as effectively a medium-sized party is no way to celebrate Labour's centenary. The prospect those List MPs could be looking in the Situations Vacant come October was focusing minds.
There were whispers about the nuclear option of forcing a leadership change, not necessarily to win the election but to try to shore up Labour's vote from a catastrophic low. Ironically, Cunliffe's opponents Jones and Robertson may well have stopped those musings turning into a more concrete push. Some had discussed putting Jones up as that last-minute leader because he could have an immediate impact on the polling.
He took himself out of the equation by resigning. Robertson helped forestall any such move by his dogged pursuit of Collins, ensuring it distracted from Labour's woes, giving voters time to forget and for the polls to rally. David Parker also helped, delivering a monetary policy statement that actually had some relevance to everyday people, although he has so far fallen short on delivering the numbers needed for people to assess what it means to them.
Cunliffe, meanwhile, embarked on the perilous job of a reshuffle. It was presented as a mini-reshuffle, simply because of the need to allocate Jones' portfolios. Closer analysis revealed it was a bit more than that. Phil Twyford and Trevor Mallard were both promoted. Both had acted as the "numbers men" against Cunliffe in former leadership battles.
The perilous part came with the demotions, which included education spokesman Chris Hipkins, who is entitled to feel a bit peeved at being jilted off the front bench to make way for Nanaia Mahuta simply because she has Maori affairs. He also demoted Darien Fenton, and Maryan Street, a former party president who is widely respected in caucus.
It was Street who was planning a no-confidence motion against former leader David Shearer last year, news of which prompted his resignation in advance of it. Street wasn't motivated by any vendetta against Shearer, simply by the awareness Labour could not win on those numbers. Shearer's polling then was significantly higher than Cunliffe's.