Unfortunately Mr Keedwell is a pillock.
He began by returning his plea form with "No case to answer" written across it. Only a court can decide whether or not he has a case to answer and they do that only when they have heard the evidence from the prosecution.
I believe he was badly advised. He should have been told that approve speed measurement devices are assumed to be working properly unless the contrary can be proved. He was suggesting that his occasional glance at his speedometer was to be relied on more than a measurement taken by an approved device. That being the case the burden shifts to him to prove it. Very often when speeding offences are defended on the basis of a faulty reading, experts are enlisted (as Mr Keedwell did). They usually try to cast doubt in the minds of the court by saying that there is a possibility that the reading may be false. That is insufficient. They must prove that a false reading actually was taken on the particular occasion in question. They clearly failed.
Mr Keedwell was found guilty in the Magistrates' Court and again in the Crown Court following hs appeal. His appeal would have followed the same procedure as his original trial, only it would have been presided over by a Crown Court judge and two Magistrates. Each of the three would have had an equal say when judging matters of fact (on which his case rested) and both tribunals found against Mr Keedwell.
I'm not surprised. Courts are reluctant to place undue weight on the evidence of experts brought in and paid for by the defence. They will obviously say what the defendant wants them to say, otherwise they would not be there.
The saddest (or perhaps most ridiculous) aspect of all this is that Mr Keedwell would almost certainly have been offered a speed awareness course for the offence. This would have cost him about £90 and half a day of his time, but no points on his licence. But I suppose if it is a principle he is defending, that doesn't really matter.