Alighting at South Bermondsey this evening I was greeted by a group[1]
of ticket inspectors complete with those hand-held Oyster readers.. On
extracting my Barclaycard/Oyster OnePulse card from my wallet the
inspector grunted "Oh, it's one of those" and waved me on.
Are the handheld readers somehow incompatible with these cards then?
Or is it just a ticket inspector who's faced with something slightly
different and doesn't think it's quite worth the effort...?

-cj

[1] Is there a collective noun for grippers/ticket inspectors?