Surely if you knew you had a persistent cough, you’d have a bottle of water handy at all times during a recording
You are assuming Whittock would have been allowed to take a bottle of water in to the recording. You are also assuming he would have anticipated that conditions in the studio would trigger his coughing. His coughing is mainly caused by hay fever and a dust allergy. He may have thought he would be safe in a TV studio. In any event, you clearly think you know better than the medical experts who gave evidence - and no, there wasn't a "cough expert" professor. There were medical experts whose expertise includes coughs.
I also find it hard to believe that anyone innocent and hoping to have their conviction overturned would, within a few years, pick up another conviction for fraud!
It was the kind of fraud that many people commit routinely - failing to declare previous claims when taking out an insurance policy. The prosecution claimed that Ingram deliberately didn't declare previous claims as he knew he wouldn't be insured. The defence claimed Ingram had simply forgotten about the previous claims which appear to have been made around 3 years before he took out this policy.
And the "within a few years" mischaracterises what happened. The conviction was within a few months of the Millionaire conviction and the offence was committed two years before he appeared on Millionaire. If he had not been convicted in the Millionaire case he probably wouldn't have faced prosecution in this case.