Baggersup.
Since T5 has only one airline, BA, using it - wasn't your eJ friend talking about BA? I have heard of BA transit passengers being told they had 'missed' their connections, before taking the escalator up to security, if they were within the designated period of time. (Which I also heard was 40 minutes).
However IMHO this is NOT the way to solve the real problems. It just lets them lie (telling only part of the truth is one of the better ways to lie - RH) about their performance.
After a decade of poor treatment by BA staff (mostly on the ground, but occasionally in the air), being xxx'ed around by strikes, etc. I have voted with my feet. Never again. I was gold for much of that decade as well.
Swiss and their Skyteam buddies now get my money - and no, they are not perfect, but they are consistently better than BA and their One World friends.