I actually experienced this in St Pancras International last week! The train stopped in the station, but the doors didn't open for a good 5 minutes. The driver

I actually experienced this in St Pancras International last week! The train stopped in the station, but the doors didn't open for a good 5 minutes. The driver issued a statement stating that there'd be a slight delay before the doors opened. I recall thinking: what possible reason could there be for not opening the doors? Congestion? Electric failure? Well, turns out it's the most ludicrous one.