She was once a CIA agent. That’s what we learnt recently about Anne Sacoolas, although it feels like we find out something else unsettling about the traffic collision she was involved in every week. 

Sacoolas is the American charged with death by dangerous driving after allegedly crashing into and killing Harry Dunn, 19, who was riding his motorbike near RAF Croughton – a secret US military listening post near Brackley, Northamptonshire – last August.

Sacoolas reportedly exited the gates at Croughton and turned on to the wrong side of the road for long enough to collide with Dunn. We’ve also learned that it took 40 minutes for an ambulance to reach the scene. Harry later died in hospital.

At first, Sacoolas co-operated with the police, but after an initial interview, she claimed diplomatic immunity and fled the country. 

What else have we learnt? That the US military doesn’t routinely train its UK-based personnel to drive here. When it does, incidents reduce by 50%. We’ve also learnt that, as the prime minister conceded last week, the UK-US extradition treaty is skewed in favour of the US.  

We’ve learnt the US secretary of state, unprecedentedly, is disinclined to grant the UK’s extradition request for Sacoolas, and that she won’t return voluntarily. Her lawyer, astonishingly, claimed “a criminal prosecution with a potential penalty of 14 years’ imprisonment is simply not a proportionate response”, as if the UK’s justice system, considered a paragon of fairness and rationality by the myriad of nations who modelled theirs on it, is cruel and deficient.

And we’ve discovered how this series of setbacks and revelations, which would break most of us, has exposed the extraordinary resolve of Dunn’s family and their supporters. If the US has underestimated them (as I think president Donald Trump did when he met Harry’s parents, only to tell them that Sacoolas was waiting in an adjoining room, in what the family described as an “ambush”), I think it has made a grave mistake.

As it stands, Dunn's family are still exploring options, including pushing for Sacoolas to be issued an Interpol ‘red notice’, which could lead to her arrest anywhere outside the US, or to be tried in her absence. 

There’s still disagreement between the family and Foreign Office over whether Sacoolas had, or was entitled to, diplomatic immunity – a vital tool for allowing government relations to function without malign interference from host nations. But it wasn’t designed for incidents like this.