Minimum connection time change makes itinerary "illegal"

Most Flyer Talkers are aware that airlines publish minimum connection times (MCTs) at various airports for connecting between certain flights.  These are the minimum “legal” connection times – ie the airlines won’t allow you to select flights with a shorter connection unless the passenger waives the airline of all responsibility for making the onward flight.  (As I experienced myself recently, you can book flights with illegal connections by phone, not online, but a note is added to your record that you’ve waived your misconnection rights.)

Anyway, ignats asks for advice when the airline’s published MCT expanded making the purchased itinerary “illegal” for the connection at London Heathrow (LHR) between British Airways and United Airlines.  The MCT change is due to the opening of BA’s new terminal 5 (T5) later this month.