Be interesting to find out if there was any IT display issues at T5 that evening. This does happen. A few years back I was in GF waiting for my Manchester flight to come up. The displays in GF was still showing Wait in Lounge. It was only happen chance one of us went down to F&M to buy some cheese, it was noticed on the displays downstairs the flight was in status “Closing”. Fortunately it was A21 so we made it! And yes we also do use the APP and it wasn’t showing gate info on that occasion!
I’ve also had an incident whereby again a flight to Manchester was running late due to late arriving aircraft. The Gate was ‘A’ at one point then changed to ‘B’ Gates. I held my ground as reckoned I could manage another champagne or 2 in GF. Half an hour later the ‘B’ had gone and was now ‘A’ again. FFS! How many people unwittingly went on the transit to B gates I wondered……..
The Heathrow public display system is not infallible, and I’m sure isn’t today either!