WE’VE all been on the receiving end at some point. A sales pitch that isn’t going quite to plan, a salesman resorting to ever more desperate tactics to try and seal the deal.

Perhaps a contract has been produced, and a wee bit of pressure is being applied. Don’t worry about all that small print, he says, in what he hopes is a breezy tone. He coughs, and adjusts his collar. “That’s just some technical stuff,” he mumbles, as his cheeks redden.

A query about the wording of a clause is met with a wave of the hand. “You’ve already agreed to that, remember? I explained that part already. Nothing to worry about. Now if you could just sign here, here and here…”

Hesitation, red flags, a desire to phone a friend, or sleep on it, or walk away. But he’s insistent. This is standard wording for a contract, he assures you. It’s like when you’re downloading the latest software update – no-one actually reads any of that stuff, surely? Yes, you might be giving them permission to harvest your data, or your vegetable plot, or your vital organs, but it’s not very likely, is it? Scroll, scroll, scroll, “accept”. No harm done.

But with the deal that’s on the table now, it seems you’ve potentially got quite a lot to lose. Yes, the salesman said something about things staying exactly the same – in fact, his exact words were “it’s about just keeping everything exactly the same as it is now” – but if that’s really the case, why is he quite so keen to sign you up? The contract seems to mention giving things away, and not getting them back for a while.

“This bit where Clause 11 is scored out, and Clause 15’s been written in instead…”

“Oh, nothing to worry about, all that’s just boilerplate text.”

“But it mentions something about seven years…”

“Why don’t we just leave aside the contractual hoo-ha?”

“Well I wouldn’t call it hoo-ha, it’s kind of the whole point of the…”

“But remember we already agreed on all of this technical detail?”

“I don’t really remember that, no.”

“Come on now, let’s not bicker. Here’s the pen…”

An awkward silence. The air conditioning hums as you read that rewritten clause one more time. He wipes his forehead with a handkerchief, then nervously picks a biscuit crumb out of his beard and eats it.

We all know the outcome. Wales signed, but on Tuesday Scotland said no. Not just the SNP, not just the SNP and their pro-indy pals the Greens, but MSPs from every party but one. It was almost as though elected representatives from across the political spectrum had actually read and considered the deal on the table, before deciding to reject it.

It was almost as though – gasp! – this wasn’t actually all about independence.

Suddenly the broken record that had served the Tories so well since 2014 was sounding a bit off-key. In fact, the lyrics weren’t even as clear as they used to be. It was definitely supposed to go “Do-do-do do, it’s all about indy” – but someone just said they heard “It’s all about yanny”. What witchcraft is this? What if all this time some people have been hearing “yes please” when the others hear “no thanks”? What if the Union flag isn’t actually red, white and blue but gold, white and laurel? What’s going on?

While his colleagues headed into the recording studio to lay down their new hit single, “Everyone Else Is Just Stupid”, the bold David Mundell went on the BBC’s Good Morning Scotland to explain why yes, the customer is always right ... except in this particular case, where the customer is not only wrong but too dim-witted to even understand what the deal is all about.

Musical theatre fans will be familiar with the tactic of “razzle dazzling”, whereby jurors are distracted from important legal arguments by the manipulative performance of a charismatic lawyer. Unfortunately, David Mundell is no Billy Flynn, and what worked in Chicago won’t fool the citizens of Caithness or Cumbernauld.

Instead of smooth-talking, we got a hesitant ramble about this “very, very technical issue” that MSPs were foolishly bickering about. Instead of tap-dancing, we got a comedy routine about how The Vow was “enacted in the Scotland Act 2016”. Perhaps Mundell was counting on the laughter drowning out the next part of his script, where he strongly implied that the vast majority of MSPs (excluding, of course, Mundell Jnr and his Tory pals) had fallen victim to a “fundamental misunderstanding” that had lead, incomprehensibly, to a big old debate that culminated in Scotland scrolling, scrolling, scrolling then clicking “Aye, nice try”.

So where does this leave us? Will the anti-EU contingent at Westminster keep on bellowing out their “Brexit means Brexit” anthem every time exasperated negotiators ask for clarification of how a currency agreement, or a currency arrangement, or some other currency half-baked-nonsense would actually work? Will Jeremy Corbyn reveal he had misheard all along and thought this something to do with having eggs for breakfast?

Most importantly, are the Brexiteers going to stick to their guns even if it means waving goodbye to the canny Scots, who know better than to simply sign the rights of their own parliament away?

We won’t be fooled by Mundell’s suggestion we are too stupid to understand. The devil is in the detail. No deal.