And because he could, he did. Compared with Shearer, Key said, former Prime Minister Helen Clark was "much, much tougher, obviously". He went on to add scathingly that "even Phil Goff was".
And despite Key's claims that he was not bothered about the happenings in Labour, he appeared to be paying a great deal of attention indeed and had even compiled a list of one-liners to make the most of it. So when the Speaker observed Key had been "mercifully brief" in a jibe about Labour's Grant Robertson, Key was quick to state that "mercifully brief" was also a good description of Shearer's tenure as leader.
In politics, nice is a luxury. It is also a fine line. Not nice enough and people don't like you. Too nice and you're a soft touch.
In general, cunning is a better attribute. Take David Cunliffe, for example, an entrepreneurial figure when it comes to political capital. Cunliffe is a man who knows how to make opportunities while stopping just short of giving those suspicious of his intentions any ammunition to accuse him of undermining his leader. Witness Tuesday night when Helen Clark spoke at Victoria University. Cunliffe swanned in late, ensuring everybody saw him. He then decided the most convenient seat was right at the front next to the chair with "Helen Clark" written on it. This ensured he was first in line for the post-speech handshake (and tacit endorsement) from the Beloved One.
Meanwhile, Shearer was back in his office trying to bat away the swarming attack of kamikaze left-wing bloggers - the Ken Rings of the Labour Party apparently racing to be first to predict his downfall, if not force it to happen so they can claim credit for it.
Astonishingly, the hoopla may have done Shearer more good than harm. Just as a fright will get rid of the hiccups, so too it appeared to get rid of Shearer's attack of 'ums and ahs'. He was not feeling very nice about the bloggers - and that anger apparently focused the mind magnificently. As a result, Shearer gave his answers clearly and concisely, making it one of the few occasions noteworthy not because of his bumbling and stuttering, but because of the lack of it.
His caucus colleagues, meanwhile, were preparing for the usual questions that come when a leader is under attack. Members of Parliament take two approaches when confronted with such questions. The more senior MPs - especially those most often mentioned as potential leaders - cannot afford to plead the right to silence. Their lot is the unequivocal pledge of loyalty and innocent denial of leadership hopes while simultaneously refusing to rule it out in the future. Little, Cunliffe and Robertson all played their part according to script.
Most, especially the more junior, scuttle by, lips pursed together as if afraid that if they say even one word they will start to channel Basil Fawlty and blurt out all manner of horrendous admissions.
First-term MP David Clark was one of the brave. He sought solace in history - albeit blasphemously - by recalling the dark epoch of the 1990s when Helen Clark polled less than the margin of error. He then pointed out, rather undiplomatically, that even at 11 per cent Shearer was far more popular than Clark had been - and Labour was trending upwards in the polls, albeit more slowly than they might like.
That is true. But Shearer lacks the two things Clark had that kept her rivals at bay, buying her the time she needed: her death stare and a band of fiercely loyal lieutenants. Nobody dared call Helen Clark "nice".