Judy Callingham - who has coached political leaders - observed that broadcasting guru Ian Fraser has "done wonders for his speech-making" ... "but no voice or media coach can change the brain patterns, and that's what's affecting his non-scripted material."
His media managers have since turned down requests for in-depth "live" interviews; hardly a vote of confidence in their boss.
But he is being wheeled out for a series of photo-ops - including with the politically savvy Auckland Mayor Len Brown - to hype-up the $1.5 billion housing affordability policy announced at the party conference.
Shearer has found - and will continue to find - it is a difficult, if not insurmountable, challenge to learn to be a political leader without having first done an apprenticeship away from the public eye.
It does not bode well for Labour to have its own leader so frightened of his own shadow that he has to banish one of his few competent colleagues to the back bench.
Unfortunately, Shearer was also simply not politically tough enough, nor sufficiently competent and astute, to have pulled off the accommodation that Australian Liberal Leader Tony Abbott made with potential rival Malcolm Turnbull this week to position his party to win the next Australian federal election.
Abbott's own popularity has waxed and waned this year while Turnbull, also a former Liberal leader, resurged in the polls. Turnbull clearly assessed his chances for a leadership tilt. But Abbott's decision to bring the former merchant banker back into the top echelons by including him in strategy and policy discussions played a part in Turnbull's own decision to bury their differences for the sake of party unity.
As the Australian newspaper put it, it was a "political bromance for unity ahead of an election".
In Shearer's case he does not have the skill to bring off an accommodation with Cunliffe. (Though in months to come he may wish he had gone down that path instead of listening to the caucus players who want the New Lynn MP buried at all costs).
Possibly, Cunliffe is also too critical of Shearer's obvious defects to want to bury his own ego for unity's sake.
The most significant outtake from the Labour conference was the extraordinary constitutional debate which historically resulted in the sole power to elect the leader being taken off the caucus and placed in an electoral college in which MPs only have 40 per cent of the total vote.
If the electoral college had been in place last year, Shearer would not have been elected ahead of Cunliffe who was (and possibly still is) the party darling. Having had power taken so comprehensively off them it is not surprising that the majority of the caucus waged war to take Cunliffe out in retribution for the campaign his supporters had run to shaft the Labour boss.
Even Shane Jones - on the outer and anything but openly supportive of Shearer in the months since he was dropped from the front-row when the Auditor-General began investigating the Bill Liu affair - summoned up some pungent comments to swipe Cunliffe en route to the caucus room.
Hypocrisy was writ large elsewhere as Cunliffe supporters openly pledged fealty to Shearer to avoid being dumped down the ranks.
But the brute reality is that if the Labour caucus was 100 per cent behind Shearer there would have been no need for a vote.
Cunliffe was a stellar Cabinet Minister in Helen Clark's Government.
He talks a good game - as was obvious when be bested Bill English in the Mood of Boardroom election debate last year in front of a bunch of business people who he mainly managed to persuade should accept Labour's capital gains tax plans.
And importantly, he has a cogent and well thought out policy platform.
Add to that the fact that he is coherent - which Shearer demonstrably is not - thinks on his feet; is capable of sustained aggression in Parliament and has guts (evidenced by the way he effectively stripped Telecom of its broadband monopoly) and he remains a politician to be reckoned with.
But not enough of his colleagues see it that way. They prefer to remain blinded to his political talents and stay with Shearer.
Shearer's speech was a doozy - it promised a new direction where "we fight back, create opportunity and build a world class New Zealand that we're proud of. A new direction that's about what is best for the long term, not just the short term. A new direction that's about all New Zealanders daring to dream and having the opportunity to get there. Not just accepting second best and managing decline."
The problem is he can't yet work without a script.