I don't think anyone was suggesting not to pay at all? The Oyster helpdesk could resolve the journey to the intended one, if the customer was allowed to tap out (otherwise it would be a maximum fare)I suppose that's the issue with Contactless / Oyster / point to point live ticketing - during times of disruption you might legitimately pay for your journey (at the reduced, diverted rate) but should you be allowed to not pay at all?
I don't see a can of worms with allowing people to pay the originally intended fare. Indeed TfL are opening themselves up to potential legal action by not allowing people to pay the intended fare.It opens up a whole can of worms that I don't think the system can deal with well.
It is down to TfL to come up with a suitable mechanism; if anyone wants to suggest a system for buses then it may be best as a separate speculative thread.Same goes for bus ticket acceptance within London - even though it is likely to be cheaper than any rail fare, should you just be allowed on? Especially if you haven't "bought" a "ticket" yet before being re-routed onto buses.
But what they can't really do is announce acceptance and then renege on it.