Which is safe. It's inconvenient, but it's safe. Failures of this sort do happen, electrical fires are probably the most extreme example. They're annoying, but nobody is at risk if you stop. Since the tube is in civilisation (even at the extreme ends of the London Underground which are outside London, like Chesham, this is hardly wilderness, you can probably see a house from where your train stopped if there aren't trees in the way) we can just walk away.
https://commons.wikimedia.org/wiki/File:Chesham_Tube_Station...
> Linus was saying no, you carry on despite the error until you get to the next station
Depending on the error the consequences of attempting to "carry on" may be fatal and it's appropriate that the decision to attempt this rests with a human, and isn't just the normal function of a machine determined to get there regardless.
There's a video of passengers doing this for real in this 2016 news article:
