This has happened before and it is totally unacceptable.
BD often has to use International or Republic of Ireland stands for domestic arrivals - which is tolerable if the buses and steps are ready and waiting. Problem comes when the stand is not as scheduled or the flight is very late. No-one bothers telling ground services that the wheels and steps are needed and ground services don't bother telling BAA staff on the first floor that dozens of people are about to arrive up that escalator.
It is a disaster waiting to happen and I have already taken the matter up with the BAA station manager at T1 and the BD station manager at LHR. I can give you their addresses if you wish to write to them yourself - much more effective than writing to CR, IMHO, although CCing the letter to Donnington Hall wouldn't hurt.