Clearly if an adjudicator (whose hands are legally tied, he cannot allow on the grounds of mitigation or it just being the decent thing to do) makes a recommendation to cancel, which is what the legislation carefully allows for, the assumption in the legislation (wrongly) being that a council will use its powers sensibly, it must be the case that if the adjudicator was instead a council employee deciding on challenges to PCNs he would have cancelled. Why don't the council cancel? because they want the money.
Before making the decision the council should be made to sit in front of the motorist and his wife and explain why they will refuse the challenge.
Remember: In London you can't park on the pavement except where it is marked out to allow it.
Outside London (in England) you can park on the pavement except where it is banned by signage.
Easy to understand how this motorist, who has enough on his plate at this time, went wrong.