If you want to throw around 1000/1 then it is 500/1 for both horses as they either get Pitt or one of a thousand

They had better start printing a caveat with the fields and form, saying that they cannot guarantee they are accurate - even so a legal eagle may have a case if he/she backs the non Pitt horse today, believing that he was to drive it (as they are the official body that release the fields)