ExRAFRadar,
I don't know the answer to your specific question whether there is anything on the ticket, however, I do have a little info that may be of help.
This is a contentious area as the Disability Discrimination Acts 1995 and 2005 do not apply to aircraft (or ships).
They do apply to the airport environment but effectively stop at the door of the aircraft.
Saying that, it doesn't require an entry on a ticket to be able to identify whether or not a person is disabled, especially not by the carer. Why should you have checked the ticket? You know he is disabled? But I take it you mean that you expected certain facilities to be made available, which were not available, and the tour operator is stating they were not made aware beforehand of the need for extra facilities.
In the aircraft it is often very difficult to cater for the needs of some disabled persons, however, designers are starting to take this into consideration. In the meantime, there are constraints placed on carriers that it is very difficult to get around, even with the best will in the world, sometimes by design limitations, sometimes by regulatory limitations.
But there is no excuse for failing to provide accessible services within an airport.
The argument would be whether the carrier (tour operator) or the airport operator is responsible for ensuring accessibility within the airport. The former would argue it is down to the latter as they are responsible for the airport and vice versa arguing that the disabled person is actually the client of the carrier.
HTH
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