MIG wrote:

But in the case described in this thread, the card had been touched at
a number of places within time limits that would have made such a
suspicion impossible. So, as long as someone doesn't disappear
mysteriously, but continues touching in and out within their capping
zones (at "continuation" places like Bow and Canary Wharf etc), what
is the justification for assuming that they could have gone outside of
the zones and punishing them accordingly?

The problem is with how the system has been coded. Until I saw the OP's
history, I assumed that if you touched a validator en route, it'd reset
your two hour time limit. As we've seen here, it doesn't.

Had the OP spent more than 15 minutes (or thereabouts) in Bow and/or
Canary Wharf, the Out of Station Interchanges would have "timed out" and
he would have been charged correctly, rather than the whole thing having
been treated as one journey.

Cheers,

Barry