We don’t normally ask you to watch videos as long as this, readers. (Although at 4m 22s it’s still not War And Peace.) As a rule the key part of any TV discussion can be boiled down to a few seconds, but this one needs to be taken in at a bit more length.

It happened on last night’s Question Time from Dundee, and was already 10 minutes into a discussion about whether there might be a second independence referendum and what might trigger it, in particular the prospect of Scotland voting to remain in the EU in June but the rest of the UK voting to leave, dragging Scotland out forcibly.

At that point, host David Dimbleby made an inexplicable intervention, abandoning his position as supposedly neutral moderator to pluck a “fact” out of thin air with which to attack the SNP’s John Swinney. Here’s what unfolded.

Wait, what?

Dimbleby’s assertion, backed up by Tory MSP Ruth Davidson and Tim Stanley of the Daily Telegraph, was that everyone in Scotland knew when they voted in the independence referendum that there was going to be an EU referendum as well.

Therefore, they said, it was untrue to claim – as Swinney had – that the No campaign had promised that a No vote meant staying in the EU (and indeed was the ONLY way to stay in the EU), and a Brexit would be a betrayal of that promise, a significant material change in circumstances and a possible trigger for a second indyref.

Now, obviously we all know that Dimbleby, Davidson and Stanley are talking complete and utter rubbish. Everyone who followed the referendum is aware that the No campaign did indeed promise exactly that, time and again:

The UK government’s “Scotland Analysis” paper on European issues is a hefty 120 pages long, covering the subject in comprehensive detail, yet it makes no mention whatsoever of an EU referendum. What it does say in its introduction is that:

But the staggeringly obvious truth, which wasn’t picked up amid the chaos by either Swinney or Patrick Harvie of the Greens, is that nobody in Scotland had the slightest clue whether there would be an EU referendum or not.

The Conservatives certainly had promised one, and they did eventually include it as a concrete commitment in their manifesto, published some months after the indyref. But Labour were opposed to a referendum on the EU, and had been since January 2013.

Throughout 2013 and 2014 Ed Miliband’s party had a comfortable lead in the opinion polls – in September 2014, the month of the indyref, their average lead was 3.9%.

Now, readers of Wings Over Scotland knew better, but as far as every newspaper and pundit in the land was concerned at that point Labour were going to win the election. Indeed, in a shock twist, Ruth Davidson herself had said in an STV debate that month that a Tory victory in the election was “not likely by the polls”.

And she’d gone even further than that. In the debate (held at the Assembly Rooms in Edinburgh, just 16 days before the vote), she’d made the proposition crystal-clear:

We apologise for the poor sound quality on that clip, but it’s still easy enough to make out the words:

“It’s disingenuous of Patrick [Harvie] to say that No means out and Yes means in, when actually the opposite is true. No means we stay in, we are members of the European Union. And yes, IF the Conservatives win the next election – which frankly isn’t looking likely by the polls, but we’re trying our best – we will allow people to have their say.”

It’s probable that only a Tory majority, not just a victory, would have ensured that the EU referendum took place. With Labour, the SNP and the Lib Dems all opposed (on top of bitter, decades-old divisions within the Conservative Party itself on the subject), a minority Tory government would very likely have failed to get the bill through.

And right up until election night nobody thought there was a cat in hell’s chance of that outright majority. When the BBC’s 10pm exit poll suggested the Tories would get as many as 316 seats – still 10 short of a majority – astonished studio pundits Paddy Ashdown and Alistair Campbell promised to consume various items of clothing.

Finally, exactly six months before the referendum day the then-Secretary of State for Scotland, Alistair Carmichael MP, had stunned the audience at a National Farmers’ Union Scotland debate in Stirling, as reported by the Farmers’ Guardian:

The widely-held expectation in September 2014, therefore, was that there was in fact NOT going to be an EU referendum. The subject just isn’t even up for debate. The claim that everyone was voting in the indyref knowing that the UK’s membership of the EU would soon be in the melting pot is an absolute, categorical, flat-out lie.

And while it would be bad enough if that lie had originated with one of the panellists, who are politicians and pundits and therefore in essence liars by nature, that it should have come, unprompted, from the supposedly neutral BBC host is a jaw-dropping dereliction of the state broadcaster’s founding principles.

We still can’t quite believe it happened. But the evidence is right in front of our eyes.