In message , at 14:54:26 on Thu, 26
Jun 2014, tim..... remarked:
I am not sure what people expect but how is a card reader expected to
"know" which card to debit if you have a couple of contactless payment
cards in your wallet? (More of an issue on buses at the moment)

It certainly seems reasonable that the reader should be "intelligent"
and look for:

Freedom pass
Oyster with relevant season
Oyster with PAYG balance

before randomly selecting debiting your CC

Even if it can't (for whatever technical reason TfL can think of)
actually intelligently charge the correct card from the above list , it
should certainly decide not to charge the CC if one of the others is
found.

It can't, and doesn't, do all that in the short interval it has
available. Even if the RFID interference between the different cards
means you could even read them individually.
--
Roland Perry