The Russian guest on a provincial radio phone-in was apoplectic with simulated outrage.
He was told there were two explanations for the state-sponsored poisoning in Salisbury that left two people fighting for their lives.
The first was there was no plausible alternative to Russian state responsibility for the attack. The British government view is shared by the US and the European Union.
The second position is that somebody else did it. This Russian guest outlined the theories that sustain this viewpoint.
It was ISIL fighters returned from Syria. These people were “freely” allowed to return to Britain and experienced in chemical weapons handling.
Or it was British intelligence gone rogue. Britain has a well-stocked defence laboratory near the town of Salisbury. The intelligence services were out to destabilise and undermine an already weakened British government.
Or the inventor of Novichok had defected to the US in 1996 and given all his secrets to the CIA. Stating that Sergei Skripal, the retired double agent, was an author of the salacious Trump dossier, the guest posited the US tried to kill him on behalf of President Trump.
I could go on with more breathless theories but Moscow’s case is that it was somebody, indeed anybody, else.
In a world filled with false equivalence, it sows confusion, or at least saps the intensity of the accusations.
Over time Russia can hope to slip the noose of sanctions and normalise its deadly game.
The Skripal case has so far been a fairly textbook example of how the Kremlin manual works.
It is not just Moscow that plays this game but a whole host of cornered regimes play on the heightened ambiguities in just the same manner.
Once equivalence has been established, the next part of the pattern places a question mark over the motives of both the accuser and accused.
Why would the Russians target a man who was handed over in a spy swap in 2010 after spending time in a Russian prison for his traitorous activity?
For a start the attack presented Vladimir Putin with a set piece showdown with the West that boosted turnout in this month’s presidential election. His prize is six more years as leader of Russia.
But asking the question leads to the bigger picture and opens other avenues of doubt. In this case does the British government seek to exploit Russophobia to consolidate its position within the Western Hemisphere?
This crisis could indeed give Britain an opportunity to define its global place post-Brexit. At some point, the British will have to decide what London’s goals are in confronting Russia.
That decision could easily create a direct British vs Russia showdown for each country’s place in the world. A head to head rivalry in which there will be one winner, or more perhaps even a new template for international relations.
That’s why countries in Europe, the Middle East and elsewhere need to start making some choices, both as a result of events and the mockery Russia has directed at the allegations.
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All countries that aspire to uphold international law must consider what’s at stake in London. If it can happen to a nuclear power, it can happen anywhere. Britain is asking for support to uphold the principle that perpetrators pay a proportionate cost for extra-judicial, cross-border killings.
The deliberate use of the most dangerous weapons of mass destruction to contaminate and kill surely cries out for a firm stance. Several others have been poisoned in Salisbury, including a police officer who was hospitalised and now says his life will never be the same again. A handful of other Russians have died in suspicious circumstances in Britain, as well as the Gulf and elsewhere.
The uncertain health conditions of Mr Skripal and his daughter mean there is much more ground to cover until London has completed its case. An investigation by chemical weapons inspectors is only just getting underway. Then there will be a diplomatic challenge to make sure there is accountability.
Plenty of time for Russia continuing to seed doubt at every turn. In the meantime it is imperative to speak clearly and robustly against the Salisbury and other Russian attacks. The slippery slope is an anarchic world of impunity and spiralling rivalry.
It is remarkable the Russians find their tools of misinformation so powerful. For example their embassy in London has put out mashed up social media images of Hercule Poirot, claiming the British need the fictional detective's powers of deduction in Salisbury.
The embassy does this with a blithe disregard. The campaign is impervious to their main argument that scientific proof is needed, not Poirot-like declarations of blame.
Playing the world for fools is the real name of the game for Mr Putin’s Russia.