In message , Mizter T
writes

More the latter I'd suggest (albeit without the two fingers) - it
sounds like what passengers have to do (as per the system design) is
touch-in again when heading down to the Tube platforms (i.e. it's
configured as an out-of-station interchange, aka OSI) - however whether
there's anything to communicate this to pax is another matter.

There's a discussion of this issue at
http://www.oyster-rail.org.uk/2011/0...finsbury-park/

Apparently there are posters explaining the new arrangements, but not
everyone thinks they are very prominent.
--
Paul Terry