Three conflicting accounts, triple negatives and an operational contradiction – the pilot scheme run by the UK Border Agency was so successful it was canned and the official responsible was sacked.

It is to the credit of the Home Affairs Select Committee that they unravelled it. The thing is such a cat's cradle, be glad that the superficial impressions can guide us. We have Brodie Clark wading in with a flat contradiction of Theresa May's account of the fiasco. He is Scots. He is old. He is a little rigid. He has a weathered, clean-shaven face. He is the injured party with 38 years of service "and a reputation gone in two days", as he put it.

Then we have Rob Whiteman (what a name for an immigration director). He is younger and metropolitan. He looks like Ben Elton will when he puts on 15 stone. He has a beard. He wasn't in the job six weeks before suspending Mr Clark. He used to be the chief executive (strictly speaking, the fat-cat chief executive) of Barking and Dagenham Council.

Then we have the committee. Keith Vaz – this is such an unlikely thing to say I'm not sure anyone has dared think it – is wonderfully impartial, and is quite as forensic as counsel.

So – Mr Clark's defence boils down to one assertion: he never reduced checks to speed up queues. "I am no 'rogue civil servant'," he said. The extra reductions, unauthorised by ministers, were just ordinary practice applied from another policy suite.

There was good questioning from Steve McCabe, David Winnick, Nicola Blackwood with her doubtful face, and Michael Ellis. But Lorraine Fullbrook put her finger on the point when she got Mr Clark to accept he had asked for fingerprint checks to be suspended before the pilot, was turned down, but reduced them anyway.

It seems to let Ms May off and makes Mr Whiteman more right than wrong. But it also looks like Whiteman stamped his authority on his new job by making an example of Mr Clark. Unwise. He also dropped the perm-sec Dame Helen Ghosh in the hash. Most unwise. This one has a good deal left to run.

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