“We’re in jail, dude,” is the unforgettable line from the cockpit video that appears to show the “friendly-fire” attack that killed Lance Corporal of Horse Matty Hull.

This was a mistake that should never have happened. It is not among the few cases, these days, that might be justified by the “fog of war”.

All the same, after watching the video, many will sympathise with the pilots of the two US A10 aircraft that fired on the British convoy near Basra. As they realise what they’ve done, the recording breaks up into anguished swearing; they could not be more stricken or berate themselves more harshly.

The same cannot be said of the Ministry of Defence and the Pentagon.

The MoD told Lance Corporal Hull’s family that some classified material could not be released to the inquest, but did not reveal the existence of the recording. It then said that it could not release the tape without authorisation of the US military. But the Pentagon refused to give the video to the family, saying that only the MoD had clearance to see it.

Some argue that friendly-fire incidents are inevitable in conflict, given the confusion and stress of combat. But forces have gone to great lengths to improve the ways of avoiding these mistakes. In Iraq, British vehicles carried orange panels to identify themselves to aircraft.

In the case of the attack that led to Lance Corporal Hull’s death, a series of mistakes led to the final, disastrous decision. Even though the pilots spotted the “orange things” on the vehicle roofs, they convinced themselves that they were rocket launchers. Their confusion about the significance of the symbol was perhaps a weakness of training.

They were then given firm but completely wrong assurances from one of the controllers on the ground that there were no coalition vehicles near by: “That is an affirm — you are well clear of friendlies.” The mistake may have arisen from confusion about which zone they were discussing, but nowhere in the recording is there an attempt to check.

Finally, after minutes of swooping and rolling over the convoy to get a better look, the pilots went ahead and fired, while still in some doubt.

Bryan Whitman, a Pentagon spokesman, said that the pilots had “followed the procedures and processes for engaging targets”. If so, those procedures need changing, but it is hard to see that they and their colleagues on the ground really did comply with the rules.

The pilots’ almost immediate realisation of the mistake, and the confirmation that they had killed one soldier, must produce sympathy for them, even if it does not change the judgment about the basis of their decision.

In the most anguished part of the recording, they alternate between the clipped, formal acknowledgement that they will abort the mission and “RTB” (return to base), and cursing in despair at the undoable mistake.

The MoD has been jolted into something like contrition by the leak of the recording; the Pentagon less so.

British officials have rushed to say that they tried to persuade the US to release the tape to the family, but it would not. The MoD said yesterday that it had not intended to deceive the family by withholding its knowledge of the recording, but this is disingenuous; it hardly helped them. The leak is an embarrassment to the British Government, which went along too quietly with the US stonewalling.

The US can legally refuse to have the pilots give evidence at the inquest, but it has a harder job morally explaining its refusal to help an ally when it had important facts to hand.

The US Embassy in London added farce to that insult yesterday when it said that the US was “considering declassifying” the video, which has now been seen around the world.

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