In message , at 20:38:56 on Tue, 24 Jun
2014, Mizter T remarked:
Card clash is not news. Has been discussed in the past on utl (in
particular I recall a particularly tabloid-esque subject line from Mr
Perry).

"TfL admits to card-clash" 4th Feb. Sounds pretty matter of fact to me.

I've been reporting Oyster card-clash here for years (originally as a
result of having a credit-card sized door-entry rfid in my wallet).

We also speculated on how they were going to prevent card-clash with the
Barclays Onepulse combined Oyster and credit card; it didn't occur that
the was "they won't", and that it need to be withdrawn.

Of all the risks listed by the OP, by far the most serious is the "pair
of unresolved journeys" one.
--
Roland Perry