I still believe they are guilty
I have never believed they are guilty.
There is the unlikeliness of a plot being hatched in a brief telephone call, Ingram trusting that someone he had never met would be able to answer all the questions (indeed, someone whose own performance in various quiz shows was poor, making him a very unlikely candidate to help Ingram cheat) and being able to pick out coughs from this individual. But above all there is the scientific evidence the jury weren't allowed to hear.
Professor Morice was able to show that the 19 "significant" coughs relied on by the prosecution were made by at least two people, not one. Unfortunately for Whittock and the Ingrams, the technique Morice used was new and had not been peer reviewed, so the judge rightly did not allow the jury to hear his evidence. That technique has now been peer reviewed and shown to be valid. If that evidence had been presented to the jury it would have blown the prosecution case out of the water.
There is also the question as to why Celador were allowed to retain the tapes and enhance them for the trial instead of them being seized by the police and examined independently.
The entire case came about because Celador (the makers of Millionaire) thought that Ingram was too stupid to win, ignoring the fact that he has two degrees and is a member of Mensa. On the back of that Ingram has not only not been paid the £1 million I believe he won fairly, he has lost his army career and I understand the Ingrmas have been declared bankrupt four times. I believe Celador ruined an entirely innocent man.
I note that a new appeal is being prepared. I understand scientific and technological advances have been used to re-analyse all 192 coughs on the recording. The lawyers involved also say they have evidence that throws doubt on the integrity of the audio evidence. They claim there are gaps in the chain of custody of the audio evidence - if true, that means the jury should not have been allowed to hear the audio evidence.