The experience of this man is extraordinarily sad. This type of thing will continue to happen as long as the feds are in charge of airport security. Common sense and good judgement are not attributes that are encouraged in this type of bureaucracy. Rather, bullying and a "just following orders" mentality are promoted. More training will not improve how agents - on average - treat disabled people.
Since this happened on the way to Disney World, now is a good time to remember the letters that another father wrote to the company.