Key then declared to the rest of the media pack that it might "come as a shock" to them that Finance Minister Bill English did not have a spare $350 million to allocate to building a national convention centre.
It was pretty mild stuff. But it is an indication of how frustrated Key is by the public and media backlash over the SkyCity proposal.
As far as Key is concerned nothing has changed from last year when he was proactive in trying to stitch together a deal to get a convention centre built. He remains unapologetic for being so interventionist.
That is not surprising. He was getting bouquets from many quarters for being so. He is thus struggling to recognise what has changed. And in respect of the healthy forecasts of more jobs and extra tourist dollars, while you can argue about the accuracy of the estimates, nothing has changed.
Yet, everything has changed. Last year's wheeling and dealing took place against the backdrop of a pending election. Attention was focused elsewhere than on a convention centre.
The story has now shifted from being about the jobs and tourism positives to one about pokies and problem gambling negatives.
Key is right. The new ingredients in the story make for an environment ripe for conspiracies. However, the media would not be doing its job if it did not investigate the ins-and-outs of the negotiations.
Key seems to have belatedly woken up to this inevitability, arguing that if poker machines did not exist then people would simply find other avenues by which to gamble. That argument is only slightly stronger than the utterly counter-productive one mounted by SkyCity that claimed Lotto does more harm to society than its Auckland casino.
Prebble's parting shot was to suggest that those in the media who had hailed Key as being able to walk on water had now decided he could not even swim. No one is arguing that. What is happening is that Key is finding himself swimming more and more against the prevailing tides.