In message , at 17:00:46 on Sat, 2 Jan
2016, Clive Page remarked:

Any why, if all you had to do to get a free trip was to claim to have
an Oyster card, would anyone during the outage try to use a
contact-less card?

I think that's called "not understanding the exact nature of the outage
and not wanting to be caught deliberately evading fares, even if for a
short time TfL will decide not to worry about it".
--
Roland Perry