Are you saying that an "immediate profound economic shock" wasn't forecast by Osborne ?
To list all the terrible treasury forecasts that haven't occurred in the first 6 months would take hours.
Nothing to do with still being in the EU and you know it, we were going to fall off a cliff - we haven't and Remoaners are devastated.
To be honest unless we triggered article 50 the day after the referendum, it was highly unlikely we'd see a 'fall off a cliff' style crash. The economy is almost solely being driven by consumer spending at this time. This is no surprise as 52% of people are probably fairly confident the economic effects of brexit aren't going to be that bad and some people who feel the economy is going to crash may be making purchase while the going is good.
However, we are now seeing the start of higher inflation which will erode consumer spending power and I wouldn't be surprised if consumer spending starts to grind to halt due to normal cyclical ups and downs before inflation is factored in.
Another issue is that inflation is eroding the probability of firms. Now usually the first things firms do is absorb those costs which we are seeing but if it looks like there is likely to be long period of inflation they will start to pass on the price to the consumer.
So we see a reduction in real consumer spending and therefore firms sales reduce. Again if firms believed this to be a short term phenomena they may choose to simply wide it out. However, with the uncertainty caused by brexit, firms will play if safe and start reducing costs by getting rid of workers.
Finally this reduces consumer spending even more and everybody is buggered as the economy goes into recession.