There is a different truth creed for politicians than witnesses in court, where the usual vow is the truth, the whole truth and nothing but the truth.
On the political stage, the whole truth is often the enemy, although not quite so much of an enemy as being caught out telling a lie. Unfortunately, many politicians find out the hard way that when the whole truth belatedly emerges, they need the sidestepping skills of Super rugby player Tim Nanai-Williams to extricate themselves successfully.
Key appears to take the same approach to the truth as to the economy: it should be flexible enough to withstand shocks.
Sometimes he is too honest, as in his revelation that he had a vasectomy. Sometimes he is not quite honest enough, although he is usually careful not to veer into actual fibbing.
Rather, he indulges in the science of obfuscation - a highly technical speciality.
When Key was first asked about his links to Fletcher by Labour MP Grant Robertson in Parliament, he revealed he had known Fletcher since he was a child and dismissed Robertson's questions as a "conspiracy" in which Key's mum was best mates with Fletcher's mum. He was subsequently asked twice whether he had, directly or indirectly, played a part in the appointment. Key did not go so far as to deny playing any role. Instead, he stuck to saying Fletcher was appointed by State Services Commissioner Iain Rennie.
Key came closer to telling an out-and-out porkie when asked by the media about it later. Asked again what role he had played in the appointment, Key said: "Only that the State Services Commissioner came to me with a recommendation. It's normal."
The trouble with obfuscation is that when the Ferris wheel stops, it results in the type of forensic analysis that Key announced his distaste for when the police report came out into John Banks' undisclosed donations from SkyCity and Kim Dotcom. Now, Key is caught in a forensic analysis storm of his own making.
Yesterday, he was arguing that it was not unusual for the Prime Minister to ring people up to suggest they apply for a job, that his involvement would have made no difference to Fletcher's chances of getting the job and, even if it had, it was the Prime Minister's prerogative to appoint the head of the GCSB anyway, so he needn't have bothered with the proper process stuff at all.
All of that simply begs the question as to why he didn't reveal his part in the saga to begin with. Key is not the only one to be kneecapped by withholding an inconvenient truth - former Prime Minister Helen Clark kept it hidden for six months that Sir Owen Glenn had informed her he had given a donation to Winston Peters. She sat silently through Peters' subsequent public denials, his "no" sign, even the beginning of the privileges committee hearing into that donation.
As Opposition leader, Key had a field- day with that, describing it as a "stunning revelation" and accusing Clark in Parliament of failing to uphold high standards by withholding the information for so long and saying that silence made her "complicit in Mr Peters' attempts to mislead the New Zealand public".
Asked why she had not come clean earlier, Clark responded that nobody had asked that particular question. Key doesn't even have that excuse.
Back on Trade Me, there is also a doodle Key did of the Beehive. He did the doodle, or one very similar, several years ago for a charity auction.
At the time, he had signed it with a flourish and a pointed barb that despite the lack of artistic merit, at least people knew it was genuine. That was aimed at highlighting his predecessor's own pistols-at-dawn duel with the truth in which she signed an artwork she had not painted.
Key's doodle was doing far better than the teapot, with a bid of $500 on it.
