Let’s go through it all once again.  The backstop set out in paragraphs 49 and 40 of December’s joint report proposes to bind at least part of the UK to the Common External Tarriff, align it to a mass of Single Market rules, and arguably maintain the direct jurisdiction of the European Court of Justice.

The EU wants the backstop for Northern Ireland only.The Government wants it, if implemented, to apply to the whole UK.   If Ministers get their way, the UK-wide settlement will be a kind of EEA minus; a Norway lite.

Either way, once the backstop kicks in, it cannot as matters stand be rescinded by one party to the agreement only. So if the EU wishes the backstop to continue to apply indefinitely (as it well might), it doesn’t matter whether the Government proclaims an end date – because, as we’ve seen, the EU isn’t bound by it.

It may be of course that the final agreement between the UK and EU supercedes what was set out in the joint agreement.  But that looks unlikely.  After all, Theresa May can’t make up her mind to back one of the two arrangements that might supercede the backstop – the customs partnership and max fac, and the clock is ticking  Even if she did, the EU might well not agree to it.

It is therefore very hard to see what David Davis has gained from the technical note on the customs agreement agreed with the Prime Minister today.

That note doesn’t bring forward the publication of the Government negotiation White Paper, which May has delayed.  It doesn’t advance preparing for No Deal if necessary, thereby putting a rocket up the Chancellor.  It doesn’t set out a route map to regulatory divergence in some cases – the subject of so much discussion at the Chequers summit.  It doesn’t remove Olly Robbins from his role as the Prime Minister’s chief Brexit negotiator, and put Davis, or another Minister, properly in charge.  It doesn’t do any of these things because they are beyond its remit.  But all of these matters have been the subject of vociferous complaint this week from Ministers and MPs – mostly, though not all by any means exclusively, Brexiteers.  They have simply not been addressed today.

Indeed, all the Brexit Secretary seems to have won is mention of a date by which the Government wants a replacement for the backstop – a “future arrangement” – to be in place: “December 2021 at the latest”.

But this is not a time limit.  It is merely the date by which the Government “expects [our italic] the future arrangement to be in place”.  ConservativeHome can expect, say, rain to fall on Sunday.  It doesn’t necessarily follow that it will.

The technical note goes on to conclude that “there are a range of options for how a time limit could be delivered, which the UK will propose and discuss with the EU”.  And as we have seen: any such limit cannot be enforced as matters stand.

It may be that some private arrangement was agreed between May and Davis that we don’t know about – that there was more to today’s discussion than meets the eye.  That is sometimes the case in these affairs.  It could also be that the Brexit Secretary has some future gambit up his sleeve, and that there will be more face-offs to come between him and the Prime Minister.  That is more likely than not, as we argued this morning – especially since he will be very conscious, this afternoon, that some are lampooning him as the boy who always cries wolf.  Remember: in the story, the wolf eventually arrives.

But, for the moment, the Government is still heading towards an autumn deal in which the EU gives vague promises of a future trade deal, but starts taking hard cash from the UK. May is no stronger, because she’s had to appease an irate minister. And Davis looks a bit weaker, because, on some matters at least, he seems to have backed down, at least for now.

More steam is rising from that simmering water.  But at least the frog has a nice shiny new button for its waistcoat.