That seems to mean that it would charge my Oyster card, my contactless
debit card, and the other Oyster card that I bought earlier in the day
to give to a friend.


It's also complete and utter nonsense, so don't waste your energy getting
annoyed about it!

There is an interesting research document about RF distance ticketing at

http://www.dft.gov.uk/pgr/scienceres...entsystems.pdf

The main conclusions seem to be that the obstacles would be primarily commercial objections and passenger acceptance rather than technical issues.