The government will do it immediately

Perhaps the most obvious thing that watching a little bit of the Supreme Court Brexit case shows is that there is an inordinate amount of paperwork, and of course I haven't read it! Presumably the High Court was not stupid.

But it seems obvious to me that during the Referendum Campaign, Mr Cameron thought that he had the power to trigger Article 50 immediately and that no one challenged that. Presumably that was relevant to the question of what parliament thought it was doing?