I think essentially the scenario being talked about, TTT, is something like: pound continues to crash, markets continue to tumble across the world, business ventures continue to be withdrawn, and just generally before we even get to triggering Article 50 we are in the grip of a recession. Under those circumstances, might the person whose responsibility it is to trigger Article 50 lose his nerve? If so, might it be the sensible choice? Leaving the EU is the will of the people, but in the scenario where everything is going horribly wrong, doesn't it just become too stubborn to go through with what would be then just too damaging a choice to pursue? Sometimes you just have to accept that circumstances have changed beyond the point where your original case, however well-intentioned at the time, is no longer reasonable (hint hint, Corbyn...)
At the moment signs are that, after the panic of the last four days, markets are stabler today, but it's more of a metastability really, and there are still a couple more months of this wait-and-see period to come. At the moment, triggering Article 50 is a matter of when, not if. On balance, I think everyone should hope it stays that way.