Originally Posted by
ScruttonStreet
I would take the same approach, but could BA in theory refuse, both in terms of letting you wait until the next flight in J was available (potentially a day or two later), and in subsequently paying your hotel bill? Wouldn't they be able to argue that they were fulfilling their obligations by offering you an earlier flight home, albeit in a lower cabin?
No. The rules are that they must transport you under similar conditions. That is widely interpreted as being in the same cabin. Theoretically, they could put you in somebody else’s business cabin without lie-flats but the scope for that between JFK and LHR is not (yet) there.