Let’s wind the state’s tatty alarm clock back. Theresa May is in the Commons at PMQs after the collapse of Carillion. Does she confess to the crime and say: “It was privatisation wot done it”?

Don’t be silly. What she said was that it wasn’t her fault because the government was a “customer” of Carillion. Perhaps she remembered hearing that the customer was always right, and this felt like the perfect get-out clause.

If the customer is always right, then I must always be right, too.

Politics is a brazen art, of course, but Mrs Maybe is shameless in her ability to spout arrant nonsense. The team of Tory monkeys in the excuses-making team did double-time on that one. Those are the same mendacious monkeys, by the way, who spin out NHS statistics for the health secretary.

The collapse of a private company working for so much of the public state was always going to be a tough one for the party that believes in privatisation.

At this point it is time to call on a phrase that it is almost obligatory for critics of the way privatisation works; it goes like this: “privatising the profits and socialising the losses”.

What this means is that private companies reap the profits when they are handed state assets to run; until everything goes wrong, at which point the state carries the can. It is an odd sort of free market that stuffs its pockets with our money – and then expects us to foot the bill when it all goes tits up, to dip into the economists’ lexicon.

The dramatic collapse of Carillion shows the weakness of the whole process, especially as the state kept bunging new deals at the company, even as profit warnings were being issued.

This is happy territory for Jeremy Corbyn, never a fan of privatisation. Watching it all go wrong is a sort of political wet dream for the Labour leader.

In an interview with the Guardian this morning, he says: “We will rewrite the rules to give the public back control of their services.” He talks about “companies like Carillion creaming off the profits” and pledges to end this “outsourcing racket”.

While it is easy to agree with such sentiments, you sense a gap here between the trusty old ideology – privatisation bad – and the day-to-day realities of government. Private finance initiatives, or PFIs, were dreamed up under John Major as a way of hiding state spending. New Labour grasped this Tory idea and made it very much their own, partly, in fairness, because the state had grown so moth-eaten following years of neglect.

As chancellor, Gordon Brown made a virtue of sticking to Tory spending plans for two years – and saw PFIs as the way out of a problem; and they’ve been costing us a packet ever since.

The problem for Labour is that private companies have been doing the state’s business for so long now, that the old infrastructure is no longer there. A Corbyn government would still end up having to strike deals with private industry.

I started with a crime scene, as it were, and here to end is another. The government’s own forensic regulator, Gillian Tully, says today that the failure of police forces to meet the official standards for forensic science make miscarriages of justice inevitable.

Outsourcing again – with Tully saying that some unaccredited labs are not subject to independent oversight.

And how did we arrive at this calamity? The government abolished the Forensic Science Service in 2012 because Tory ministers wanted to create a free market in forensics.

A case for CSI (criminally stupid ideas).